Processing apparatus with sensory subsystem for detecting the presence/absence of wafers or other workpieces

ABSTRACT

A semiconductor processing workpiece support which includes a detection subsystem that detects whether a wafer or other workpiece is present. The preferred arrangement uses an optical beam emitter and an optical beam detector mounted along the back side of a rotor which acts as a workpiece holder. The emitted beam passes through the workpiece holder and is reflected by any workpiece present in the workpiece holder. The preferred units include both an optical emitter and pair of detectors. The detection is preferably able to discriminate on the basis of the angle of the reflected beam, so that a portion of the beam reflected by the workpiece holder is not considered or minimized.

[0001]FIG. 1 is an environmental view of the semiconductor processinghead of the present invention showing two processing heads in aprocessing station, one in a deployed, “closed” or “processing”position, and one in an “open” or “receive wafer” position.

[0002]FIG. 2 is an isometric view of the semiconductor processing headof the present invention.

[0003]FIG. 3 is a side elevation view of the processing head of thepresent invention showing the head in a “receive wafer” position.

[0004]FIG. 4 is a side elevation view of the processing head of FIG. 2showing the head in a rotated position ready to lower the wafer into theprocessing station.

[0005]FIG. 5 is a side elevation view of the processing head of FIG. 2showing the head operator pivoted to deploy the processing head andwafer into the bowl of the processing station.

[0006]FIG. 6 is a schematic front elevation view of the processing headindicating the portions detailed in FIGS. 7 and 8.

[0007]FIG. 7 is a front elevation sectional view of the left half of theprocessing head of the apparatus of the present invention also showing afirst embodiment of the wafer holding fingers.

[0008]FIG. 8 is a front elevation sectional view of the left half of theprocessing head of the apparatus of the present invention also showing afirst embodiment of the wafer holding fingers.

[0009]FIG. 9 is an isometric view of the operator base and operator armof the apparatus of the present invention with the protective coverremoved.

[0010]FIG. 10 is a right side elevation view of the operator arm of thepresent invention showing the processing head pivot drive mechanism.

[0011]FIG. 11 is a left side elevation view of the operator arm of thepresent invention showing the operator arm drive mechanism.

[0012]FIG. 12 is schematic plan view of the operator arm indicating theportions detailed in FIGS. 13 and 14.

[0013]FIG. 13 is a partial sectional plan view of the right side of theoperator arm showing the processing head drive mechanism.

[0014]FIG. 14 is a partial sectional plan view of the left side of theoperator arm showing the operator arm drive mechanism.

[0015]FIG. 15 is a side elevational view of a semiconductor workpieceholder constructed according to a preferred aspect of the invention.

[0016]FIG. 16 is a front sectional view of the FIG. 1 semiconductorworkpiece holder.

[0017]FIG. 17 is a top plan view of a rotor which is constructed inaccordance with a preferred aspect of this invention, and which is takenalong line 3-3 in FIG. 16.

[0018]FIG. 18 is an isolated side sectional view of a finger assemblyconstructed in accordance with a preferred aspect of the invention andwhich is configured for mounting upon the FIG. 17 rotor.

[0019]FIG. 19 is a side elevational view of the finger assembly of FIG.18.

[0020]FIG. 20 is a fragmentary cross-sectional enlarged view of a fingerassembly and associated rotor structure.

[0021]FIG. 21 is a view taken along line 7-7 in FIG. 4 and shows aportion of the preferred finger assembly moving between an engaged anddisengaged position.

[0022]FIG. 22 is a view of a finger tip of the preferred finger assemblyand shows an electrode tip in a retracted or disengaged position (solidlines) and an engaged position (phantom lines) against a semiconductorworkpiece.

[0023]FIG. 23 is a sectional view showing a second embodimentsemiconductor processing station having a workpiece support assembly anda plating station bowl assembly.

[0024]FIG. 24 is an enlarged sectional view similar to FIG. 23 showingonly portions of the workpiece support.

[0025]FIG. 25 is an exploded perspective view of portions of theworkpiece support shown in FIG. 24.

[0026]FIG. 26 is an exploded perspective view of portions of a rotorassembly forming part of the workpiece support shown in FIG. 24.

[0027]FIG. 27 is a perspective view showing an interior face of therotor assembly.

[0028]FIG. 28 is a perspective view showing the interior face of therotor assembly with a wafer supported thereon.

[0029]FIG. 29 is an enlarged perspective view showing an actuatortransmission which mounts on the rotor assembly and controls motion ofworkpiece-engaging fingers.

[0030]FIG. 30 is an exploded perspective assembly view of the actuatortransmission shown in FIG. 29.

[0031]FIG. 31 is a longitudinal sectional view of the actuatortransmission shown in FIG. 29.

[0032]FIG. 32 is a longitudinal sectional view of one preferred form ofelectrode assembly which can be used in the second embodiment processingsystem.

[0033]FIG. 33 is a longitudinal sectional view of one preferred form ofelectrode assembly which can be used in the second embodiment processingsystem.

[0034]FIG. 34 is a longitudinal sectional view of one preferred form ofelectrode assembly which can be used in the second embodiment processingsystem.

[0035]FIG. 35 is a longitudinal sectional view of one preferred form ofelectrode assembly which can be used in the second embodiment processingsystem.

[0036]FIG. 36 is a longitudinal sectional view of one preferred form ofelectrode assembly which can be used in the second embodiment processingsystem.

[0037]FIG. 37 is a sectional view showing an enlarged distal tip portionof a further electrode before being pre-conditioned in accordance withanother aspect of the invention.

[0038]FIG. 38 is a sectional view showing the enlarge distal tip portionof the previous figure after being pre-conditioned.

[0039]FIG. 39 is a longitudinal sectional view of one preferred form ofelectrode assembly which can be used in the second embodiment processingsystem.

[0040]FIG. 40 is a sectional view showing the electrode assembly of FIG.39 in position ready to engage a semiconductor workpiece.

[0041]FIG. 41 is a sectional view showing the electrode assembly of FIG.39 in an engaged position with a semiconductor workpiece.

[0042]FIG. 42 is a longitudinal sectional view showing the platingstation bowl shown in FIG. 23.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] This disclosure of the invention is submitted in furtherance ofthe constitutional purposes of the U.S. Patent Laws “to promote theprogress of science and useful arts” (Article 1, Section 8). TABLE 1Listing of Subsections of Detailed Description and Pertinent Items withReference Numerals and Pace Numbers Workpiece Support 11 semiconductorprocessing machine 400 11 workpiece supports 401 11 Workpiece support402 11 Workpiece support 403 11 semiconductor manufacturing chamber 11404 beam emitter 81 11 operator base 405 11 processing head 406 11operator arm 407 11 wafer holder 408 11 fingers 409 11 Workpiece holder408 11 workpiece spin axis 410 11 process pivot axis 411 11 operatorpivot axis 412 12 workpiece W 12 fingertips 414 12 processing bowl 41712 left and right forks 418 and 419 13 Operator Base 14 operator baseback portion 420 14 operator base left yoke arm 421 14 operator baseright yoke arm 422 14 yoke arm fasteners 423 14 operator arm bearings424 14 operator arm 425 14 Operator Arm 14 process arm rear cavity 42615 lift motor 452 15 rotate motor 428 15 processing head left pivotshaft 429 15 processing head right pivot shaft 430 15 OperatorArm-Processing Head Rotate 15 Mechanism Processing head rotate mechanism431 16 rotate shaft 432 16 securing collar 433 16 rotate motor support434 16 rotate encoder 435 16 rotate pulley inboard bearing 436 17 rotatebelt 437 17 processing head pulley 438 17 rotate belt tensioner 439 18tensioner hub 468 18 processing head shaft bearing 440 18 processinghead rotate bearing 469 18 processing head shaft bearing 441 18 cablebrackets 442 and 443 19 rotate overtravel protect 444 19 rotate flag 44720 Rotate optical switches 445 and 446 20 Operator Arm-Lift Mechanism 20operator arm lift mechanism 448 20 lift motor shaft 454 21 lift geardrive 453 21 lift drive shaft 456 21 lift bushing 449 21 anchor plate458 21 anchor fasteners 457 21 Lift bearing 450 21 lift bearing support460 22 operator arm frame 461 22 lift anchor 451 22 lift overtravelprotect 462 22 lift optical switch low 463 23 lift optical switch high464 23 lift flag 465 23 lift motor encoder 455 23 lift motor 452 23slotted lift flag mounting slots 467 23 lift flag fasteners 466 23Processing Head 24 processing head housing 470 24 circumferentialgrooves 471 24 rotate shaft openings 474 and 475 24 left and rightprocessing head mounts 24 472 processing head door 476 24 processinghead void 477 25 Processing Head Spin Motor 25 workpiece holder 478 25spin axis 479 25 spin motor 480 26 top motor housing 481 26 spin motorshaft 483 26 workpiece holder rotor 484 26 rotor hub 485 26 rotor hubrecess 486 26 workpiece shaft snap-ring 488 26 rotor recess groove 48926 spin encoder 498 27 optical tachometer 499 27 Processing Head FingerActuators 29 Pneumatic piston 502 30 actuator spring 505 30 cavity endcap 507 30 retaining ring 508 30 pneumatic inlet 503 30 pneumatic supplyline 504 30 actuator plate 509 30 actuator plate connect screw 510 30Wave springs 529 30 bushing 512 30 pneumatic piston recess 511 30 fingeractuator contacts 513 31 Processing Head Workpiece Holder 31 fingeractuator lever 514 31 finger stem 515 32 finger diaphragm 519 32workpiece holder rotor 484 32 finger opening 521 32 rotor diaphragm lip523 32 finger spring 520 32 finger actuator tab 522 32 finger collar ornut 517 32 shoulder 518 32 finger actuator mechanism 500 33 cavity 50133 Semiconductor Workpiece Holder - 33 Electroplating Embodimentsemiconductor workpiece holder 810 33 bottom half or bowl 811 34Processing Head and Processing Head 34 Operator workpiece support 812 34spin head assembly 814 34 lift/rotate assembly 816 34 motor 818 35 rotor820 35 rotor spin axis 822 35 finger assembly 824 36 actuator 825 36rotor center piece 826 36 spokes 328 36 rotor perimeter piece 830 36Finger Assembly 37 finger assembly frame 832 38 angled slot 832a 38finger assembly frame outer flange 834 38 inner drive plate portion 83638 Finger Assembly Drive System 38 bearing 838 39 collet 840 39 bearingreceptacle 839 39 spring 842 39 spring seat 844 39 Finger AssemblyElectrical System 40 pin connector 846 40 finger 848 40 nut 850 40anti-rotation pin 852 40 finger tip 854 41 electrode contact 858 41Finger Assembly Drive System Interface 41 finger actuator 862 41actuation ring 863 42 first movement path axis 864 42 secondary linkage865 42 link arm 867 42 actuator torque ring 869 42 pneumatic operator871 42 Engaged and Disengaged Positions 43 arrow A 44 workpiece standoff865 44 bend 866 45 Finger Assembly Seal 45 seal 868 45 rim portion 87045 Methods and Operation 47 Second Embodiment Processing Station - 52Generally second semiconductor processing station 52 900 workpiecesupport assembly 901 53 processing bowl 917 53 processing ormanufacturing chamber 53 904 Workpiece Support Generally 53 rotorassembly 984 53 Workpiece Support Head Operator 53 processing head 90653 head operator 907 53 upper portion 908 53 head connection shaft 90953 horizontal pivot axis 910 53 Workpiece Support Main Part 54processing head housing 970 54 processing head frame 982 54 door plate983 54 door ring member 984 54 frame-pivot shaft connection 985 54 pivotshaft connection base 935 55 first housing part 971 55 housing cap 97255 main part mechanism chamber 973 55 peripheral groove 986 55inflatable door seal 987 55 annular rotor receiving groove 988 55Workpiece Support Rotor Drive 56 workpiece spin motor 980 56 statorarmatures 916 56 motor shaft 918 56 bottom motor bearing 921 56 bottommotor housing 922 56 top motor housing 923 56 top motor bearing 927 56fasteners 924 57 frame extensions 925 57 top frame piece 926 57Workpiece Support Rotor Assembly 57 rotor assembly 930 57 rotor shaft931 57 rotor shaft hub 932 57 shaft hub receptacle 933 57 inner rotorpart 934 57 inner rotor part hub 935 57 peripheral band 936 57 snap-ring937 57 transmission receptacles 937 57 fasteners 941 58 rotor face panel943 58 apertures 787 58 support standoffs 721 58 workpiece peripheralguide pins 722 58 reinforcing ribs 942 58 side wall 944 58 fingerpassageways 949 59 rotor shaft mounting nut 888 59 angular positionencoder 498 59 Workpiece Detection Subsystem 60 mounting 738 61 detector739 61 workpiece detector windows 741 61 Workpiece Support FingerActuator 63 finger pivot axes 953 63 workpiece standoff supports 721 63finger actuator transmission 960 64 finger head mounting receptacle 95464 locking pin groove 953 64 finger mounting pin 956 64 transmissionbase 961 64 mounting cutout 962 64 transmission shaft 963 65 shaftchannel or groove 964 65 shaft camming control member 965 65 ball 966 65ball support fastener 967 65 interior shaft passageway 968 65 springretainer 969 65 finger mounting spring 938 65 set screw 939 66transmission head 656 66 bearing 657 66 head pieces 658 and 659 66 headfasteners 660 66 head guide rods 661 66 two guide passageways 662 66head bias springs 664 66 shaft seal 667 66 transmission head depressionring 683 66 operator output connection ring 684 66 pneumatic actuatorengines 691 67 pneumatic manifolds 692 67 Electrode Fingers WithSubmerged 67 Conductive Current Transfer Areas finger assembly 631 67finger shaft 632 67 finger head 633 67 locking pin 956 67 dielectricsheathing 634 and 635 68 contact head 636 68 contact face 637 68submersion line 639 68 first electrically conductive segment 642 68second electrically conductive segment 68 643 third electricallyconductive segment 644 69 third dielectric segment 653 69 thirddielectric sheath 654 69 distal contact insert part 655 70 insertreceptacle 616 70 contact face 617 70 electrode finger 979 70 dielectricsheath 621 70 Electrode Fingers With Dielectric Sheaths 72 CoveringSubmerged Areas electrode finger 681 72 dielectric sheath 682 72 contactinsert side walls 619 72 insert contact part or tip 655 72Pre-Conditioning of Electrode Contact 73 Faces electrode 614 73 distalexposed surface 615 73 dielectric sheath 616 74 Methods UsingWorkpiece-Engaging 75 Electrode Assembly With Sealing Boot electrodefinger 583 75 electrode shaft 584 75 head 633 75 cover or boot 585 75distal contact lip 586 76 contact insert part 655 76 skirt-portion 58776 electrode shaft distal end surface 588 76 contact face 617 76substrate or other subjacent layer 561 76 thin metallic seed layer 56276 via or other opening 563 76 photoresist layer 564 76 Plating BowlAssembly 79 electroplating bowl assembly 303 79 process bowl or platingvessel 316 79 outer bowl side wall 617 79 bowl bottom 319 79 bowl rimassembly 314 79 cup assembly 320 79 fluid cup portion 321 79 cup side322 79 cup bottom 323 79 flutes 372 79 cup main joint 387 80 riser tube361 80 fitting 362 80 fluid inlet line 325 80 bowl bottom opening 327 80cup fluid inlet openings 324 80 overflow chamber 345 80 level detectors351 and 352 81 diffuser height adjustment mechanisms 82 386 mountingfasteners 389 82 Plating Anode Shield 82 anode shield 393 82 anodeshield fasteners 394 82 * * * (End of Table 1) * * *

[0044] Workpiece Support

[0045] Turning now to FIG. 1, a semiconductor processing machine 400having two workpiece supports 401 is shown. Workpiece support 402 isshown in a “open” or “receive wafer” position in order to receive aworkpiece or semiconductor wafer for further processing. Workpiecesupport 403 is shown in a “closed” or “deployed” position wherein thesemiconductor wafer has been received by the workpiece support and isbeing exposed to the semiconductor manufacturing process in thesemiconductor manufacturing chamber 404. FIG. 1 also shows an optionalbeam emitter 81 for emitting a laser beam detected by robotic waferconveyors to indicate position of the unit.

[0046] Turning now to FIG. 2, an enlarged view of the workpiece support401 is shown. Workpiece support 401 advantageously includes operatorbase 405, a processing head 406, and an operator arm 407. Processinghead 406 preferably includes workpiece holder or wafer holder 408 andwhich further includes fingers 409 for securely holding the workpieceduring further process and manufacturing steps. Workpiece holder 408more preferably spins about workpiece spin axis 410.

[0047] The processing head is advantageously rotatable about processinghead pivot axis or, more briefly termed, process pivot axis 411. In thismanner, a workpiece (not shown) may be disposed between and grasped bythe fingers 409, at which point the processing head is preferablyrotated about process head pivot axis 411 to place the workpiece in aposition to be exposed to the manufacturing process.

[0048] In the preferred embodiment, operator arm 407 may be pivotedabout operator pivot axis 412. In this manner, the workpiece isadvantageously lowered into the process bowl (not shown) to accomplish astep in the manufacture of the semiconductor wafer.

[0049] Turning now to FIGS. 3-5, the sequence of placing a workpiece onthe workpiece support and exposing the workpiece to the semiconductormanufacturing process is shown. In FIG. 3, a workpiece W is shown asbeing held in place by fingertips 414 of fingers 409. Workpiece W isgrasped by fingertips 414 after being placed in position by robot orother means.

[0050] Once the workpiece W has been securely engaged by fingertips 414,processing head 406 can be rotated about process head pivot axis 411 asshown in FIG. 4. Process head 406 is preferably rotated about axis 411until workpiece W is at a desired angle, such as approximatelyhorizontal. The operator arm 407 is pivoted about operator arm pivotaxis 412 in a manner so as to coordinate the angular position ofprocessing head 406. In the closed position, the processing head isplaced against the rim of bowl 416 and the workpiece W is essentially ina horizontal plane. Once the workpiece W has been secured in thisposition, any of a series of various semiconductor manufacturing processsteps may be applied to the workpiece as it is exposed in the processingbowl 417.

[0051] Since the processing head 406 is engaged by the operator arm 407on the left and right side by the preferably horizontal axis 411connecting the pivot points of processing head 406, a high degree ofstability about the horizontal plane is obtained. Further, since theoperator arm 407 is likewise connected to the operator base 405 at leftand right sides along the essentially horizontal line 412 connecting thepivot points of the operator arm, the workpiece support forms astructure having high rigidity in the horizontal plane parallel to anddefined by axes 411 and 412. Finally, since operator base 405 issecurely attached to the semiconductor process machine 400, rigidityabout the spin axis 410 is also achieved.

[0052] Similarly, since processing head 406 is nested within the fork oryoke shaped operator arm 407 having left and right forks 418 and 419,respectively, as shown in FIG. 2, motion due to cantilevering of theprocessing head is reduced as a result of the reduced moment arm definedby the line connecting pivot axes 411 and 412.

[0053] In a typical semiconductor manufacturing process, the workpieceholder 408 will rotate the workpiece, having the process head 406secured at two points, that is, at the left and right forks 418 and 419,respectively, the vibration induced by the rotation of the workpieceholder 408 will be significantly reduced along the axis 411.

[0054] A more complete description of the components of the presentinvention and their operation and interrelation follows.

[0055] Operator Base

[0056] Turning now to FIG. 9, operator base 405 is shown. The presentinvention advantageously includes an operator base 405 which forms anessentially yoke-shaped base having an operator base back portion 420,an operator base left yoke arm 421, and an operator base right yoke arm422. Yoke arms 421 and 422 are securely connected to the base of theyoke 420. In the preferred embodiment, the yoke arms are secured to theyoke base by the yoke arm fasteners 423. The yoke arm base in turn isadvantageously connected to the semiconductor process machine 400 asshown in FIG. 1.

[0057] The upper portions of the yoke arm advantageously includereceptacles for housing the operator arm bearings 424 which are used tosupport the pivot shafts of the operator arm 425, described more fullybelow.

[0058] Operator Arm

[0059] Still viewing FIG. 9, the present invention advantageouslyincludes an operator arm 407. As described previously, operator arm 407preferably pivots about the operator arm pivot axis 412 which connectsthe center line defined by the centers of operator arm pivot bearings424.

[0060] Operator arm or pivot arm 407 is advantageously constructed insuch a manner to reduce mass cantilevered about operator arm pivot axis412. This allows for quicker and more accurate positioning of the pivotarm as it is moved about pivot arm axis 412.

[0061] The left fork of the pivot arm 418, shown more clearly in FIG.11, houses the mechanism for causing the pivot arm to lift or rotateabout pivot arm pivot axis 412. Pivot arm right fork 419, shown moreclearly in FIG. 10, houses the mechanism for causing the processing head406 (not shown) to rotate about the process head pivot axis 411.

[0062] The process arm rear cavity 426, shown in FIG. 9, houses the liftmotor 452 for causing the operator arm 407 to rotate about pivot armaxis 412. Process arm rear cavity 426 also houses rotate motor 428 whichis used to cause the processing head 406 to rotate about the processinghead pivot axis 411. The rotate motor 428 may more generally bedescribed as a processing head pivot or rotate drive. Processing head406 is mounted to operator arm 407 at processing head left pivot shaft429 and processing head right pivot shaft 430.

[0063] Operator arm 407 is securely attached to left yoke arm 421 andright yoke arm 422 by operator arm pivot shafts 425 and operator armpivot bearings 424, the right of which such bearing shaft and bearingsare shown in FIG. 9.

[0064] Operator Arm-Processing Head Rotate Mechanism

[0065] Turning now to FIG. 13, a sectional plan view of the right rearcorner of operator arm 407 is shown. The right rear section of operatorarm 407 advantageously contains the rotate mechanism which is used torotate processing head 406 about processing head pivot shafts 430 and429. Processing head rotate mechanism 431 preferably consists of rotatemotor 428 which drives rotate shaft 432, more generally described as aprocessing head drive shaft. Rotate shaft 432 is inserted within rotatepulley 425 which also functions as the operator arm pivot shaft. Asdescribed previously, the operator arm pivot shaft/lift pulley issupported in operator arm pivot bearings 424, which are themselvessupported in operator base yoke arm 422. Rotate shaft 432 is securedwithin left pulley 424 by securing collar 433. Securing collar 433secures rotate pulley 425 to rotate shaft 432 in a secure manner so asto assure a positive connection between rotate motor 428 and rotatepulley 425. An inner cover 584 is also provided.

[0066] Rotate motor 428 is disposed within process arm rear cavity 426and is supported by rotate motor support 434. Rotate motor 428preferably is a servo allowing for accurate control of speed andacceleration of the motor. Servo motor 428 is advantageously connectedto rotate encoder 435 which is positioned on one end of rotate motor428. Rotate encoder 435, more generally described as a processing headencoder, allows for accurate measurement of the number of rotations ofrotate motor 428, as well as the position, speed, and acceleration ofthe rotate shaft 432. The information from the rotate encoder may beused in a rotate circuit which may then be used to control the rotatemotor when the rotate motor is a servo. This information is useful inobtaining the position and rate of travel of the processing head, aswell as controlling the final end point positions of the processing headas it is rotated about process head rotate axis 411.

[0067] The relationship between the rotate motor rotations, as measuredby rotate encoder 435, may easily be determined once the diameters ofthe rotate pulley 425 and the processing head pulley 438 are known.These diameters can be used to determine the ratio of rotate motorrelations to processing head rotations. This may be accomplished by amicroprocessor, as well as other means.

[0068] Rotate pulley 425 is further supported within operator arm 407 byrotate pulley inboard bearing 436 which is disposed about an extendedflange on the rotate pulley 425. Rotate pulley inboard bearing 436 issecured by the body of the operator arm 407, as shown in FIG. 13.

[0069] Rotate pulley 425 advantageously drives rotate belt 437, moregenerally described as a flexible power transmission coupling. Referringnow to FIG. 10, rotate belt 437 is shown in the side view of the rightarm 419 of the operator arm 407. Rotate belt 437 is preferably a toothedtiming belt to ensure positive engagement with the processing head drivewheel, more particularly described herein as the processing head pulley438, (not shown in this view). In order to accommodate the toothedtiming belt 437, both the rotate pulley 425 and the processing headpulley 438 are advantageously provided with gear teeth to match thetooth pattern of the timing belt to assure positive engagement of thepulleys with the rotate belt.

[0070] Rotate mechanism 431 is preferably provided with rotate belttensioner 439, useful for adjusting the belt to take up slack as thebelt may stretch during use, and to allow for adjustment of the belt toassure positive engagement with both the rotate pulley and theprocessing head pulley. Rotate belt tensioner 439 adjusts the tension ofrotate belt 437 by increasing the length of the belt path between rotatepulley 425 and processing head pulley 438, thereby accommodating anyexcess length in the belt. Inversely, the length of the belt path mayalso be shortened by adjusting rotate belt tensioner 439 so as to createa more linear path in the upper portion of rotate belt 437. Thetensioner 439 is adjusted by rotating it about tensioner hub 468 andsecuring it in a new position.

[0071] Turning now to FIG. 13, processing head pulley 438 is mounted toprocessing head rotate shaft 430 in a secured manner so that rotation ofprocessing head pulley 438 will cause processing head rotate shaft 430to rotate. Processing head shaft 430 is mounted to operator arm rightfork 419 by processing head shaft bearing 440, which in turn is securedin the frame of the right fork 419 by processing head rotate bearing469. In a like manner, processing head shaft 429 is mounted in operatorarm left fork 418 by processing head shaft bearing 441, as shown in FIG.9.

[0072] Processing head pivot shafts 430 and 429 are advantageouslyhollow shafts. This feature is useful in allowing electrical, optical,pneumatic, and other signal and supply services to be provided to theprocessing head. Service lines such as those just described which arerouted through the hollow portions of processing head pivot shafts 429and 430 are held in place in the operator arms by cable brackets 442 and443. Cable brackets 442 and 443 serve a dual purpose. First, routing theservice lines away from operating components within the operator armleft and right forks. Second, cable brackets 442 and 443 serve a usefulfunction in isolating forces imparted to the service cables by therotating action of processing head 406 as it rotates about processinghead pivot shafts 429 and 430. This rotating of the processing head 406has the consequence that the service cables are twisted within the pivotshafts as a result of the rotation, thereby imparting forces to thecables. These forces are preferably isolated to a particular area so asto minimize the effects of the forces on the cables. The cable brackets442 and 443 achieve this isolating effect.

[0073] The process head rotate mechanism 431, shown in FIG. 13, is alsoadvantageously provided with a rotate overtravel protect 444, whichfunctions as a rotate switch. Rotate overtravel protect 444 preferablyacts as a secondary system to the rotate encoder 435 should the controlsystem fail for some reason to stop servo 428 in accordance with apredetermined position, as would be established by rotate encoder 435.Turning to FIG. 13, the rotate overtravel protect 444 is shown in planview. The rotate overtravel protect preferably consists of rotateoptical switches 445 and 446, which are configured to correspond to theextreme (beginning and end point) portions of the processing head, aswell as the primary switch component which preferably is a rotate flag447. Rotate flag 447 is securely attached to processing head pulley 438such that when processing head shaft 430 (and consequently processinghead 406) are rotated by virtue of drive forces imparted to theprocessing head pulley 425 by the rotate belt 437, the rotate flag 447will rotate thereby tracking the rotate motion of processing head 406.Rotate optical switches 445 and 446 are positioned such that rotate flag447 may pass within the optical path generated by each optical switch,thereby generating a switch signal. The switch signal is used to controlan event such as stopping rotate motor 428. Rotate optical switch 445will guard against overtravel of processing head 406 in one direction,while rotate optical switch 446 will provide against overtravel of theprocessing head 406 in the opposite direction.

[0074] Operator Arm-Lift Mechanism

[0075] Operator arm 407 is also advantageously provided with an operatorarm lift mechanism 448 which is useful for causing the operator arm tolift, that is, to pivot or rotate about operator arm pivot axis 412.Turning to FIG. 14, the operator arm lift mechanism 448 is shown in thesectional plan view of the right rear corner of operator arm 407.

[0076] Operator arm lift mechanism 448 is advantageously driven by liftmotor 452. Lift motor 452 may be more generally described as an operatorarm drive or operator arm pivot drive. Lift motor 452 is preferably aservo motor and is more preferably provided with an operator encoder,more specifically described as lift motor encoder 456. When lift motor452 is a servo motor coupled with lift encoder 456, informationregarding the speed and absolute rotational position of the lift motorshaft 454 may be known from the lift encoder signal. Additionally, byvirtue of being a servo mechanism, the angular speed and acceleration oflift motor 452 may be easily controlled by use of the lift signal by anelectrical circuit. Such a lift circuit may be configured to generatedesired lift characteristics (speed, angle, acceleration, etc.). FIG. 14shows that the lift operator may also include a brake 455 which is usedto safely stop the arm if power fails.

[0077] Lift motor 452 drives lift motor shaft 454 which in turn driveslift gear drive 453. Lift gear drive 453 is a gear reduction drive toproduce a reduced number of revolutions at lift drive shaft 456 as thefunction of input revolutions from lift motor shaft 454.

[0078] Lift drive gear shaft 456 is secured to lift anchor 451 which ismore clearly shown in FIG. 11. Lift anchor 451 is preferably shaped tohave at least one flat side for positively engaging lift bushing 449.Lift anchor 451 is secured to lift drive shaft 456 by anchor plate 458and anchor fasteners 457. In this manner, when lift drive shaft 456 isrotated, it will positively engage lift bushing 449. Returning to FIG.14, it is seen that lift bushing 449 is mounted in operator left yokearm 421, and is thus fixed with respect to operator base 405. Liftbearing 450 is disposed about the lift bushing shank and is supported inoperator arm 407 by lift bearing support 460 which is a bushingconfigured to receive lift bearing 450 on a first end and to supportlift gear drive 453 on a second end. Lift bearing support 460 is furthersupported within operator arm 407 by operator arm frame 461. The liftarm is thus free to pivot about lift bushing 449 by virtue of liftbearing 450.

[0079] In operation, as lift motor 452 causes lift gear drive 453 toproduce rotations at gear drive shaft 456, lift anchor 451 is forcedagainst lift bushing 449 which is securely positioned within rightoperator yoke arm 421. The reactive force against the lift anchor 451will cause lift bearing support 460 to rotate relative to lift bushing449. Since lift bushing 449 is fixed in operator base 405, and sinceoperator base 405 is fixed to processing machine 400, rotation of liftbearing support 460 will cause lift arm 407 to pivot about operator armpivot axis 412, thereby moving the processing head 406. It isadvantageous to consider the gear drive shaft (or “operator arm shaft”)as being fixed with respect to operator base 405 when envisioning theoperation of the lift mechanism.

[0080] Operator lift mechanism 448 is also advantageously provided witha lift overtravel protect 462 or lift switch. The lift rotate protectoperates in a manner similar to that described for the rotate overtravelprotect 444 described above. Turning now to FIG. 11, a left side view ofthe operator arm 407 is shown which shows the lift overtravel protect indetail.

[0081] The lift overtravel protect preferably includes a lift opticalswitch low 463 and a lift optical switch high 464. Other types of limitswitches can also be used. The switch high 464 and switch low 463correspond to beginning and endpoint travel of lift arm 407. The primarylift switch component is lift flag 465, which is firmly attached to leftoperator base yoke arm 421. The lift optical switches are preferablymounted to the movable operator arm 407. As operator arm 407 travels inan upward direction in pivoting about operator arm pivot axis 412, liftoptical switch high 464 will approach the lift flag 465. Should the liftmotor encoder 455 fail to stop the lift motor 454 as desired, the liftflag 465 will break the optical path of the lift optical switch high 464thus producing a signal which can be used to stop the lift motor. Inlike manner, when the operator arm 407 is being lowered by rotating itin a clockwise direction about the operator arm pivot axis 412, as shownin FIG. 11, overtravel of operator arm 407 will cause lift opticalswitch low 463 to have its optical path interrupted by lift flag 465,thus producing a signal which may be used to stop lift motor 452. As isshown in FIG. 11, lift flag 465 is mounted to left operator base yokearm 421 with slotted lift flag mounting slots 467 and removable liftflag fasteners 466. Such an arrangement allows for the lift flag to beadjusted so that the lift overtravel protect system only becomes activeafter the lift arm 407 has traveled beyond a preferred point.

[0082] Processing Head

[0083] Turning now to FIG. 6, a front elevation schematic view of theprocessing head 406 is shown. Processing head 406 is described in moredetail in FIGS. 7 and 8. Turning now to FIG. 7, a sectional view of theleft front side of processing head 406 is shown. Processing head 406advantageously includes a processing head housing 470 and frame 582.Processing head 406 is preferably round in shape in plan view allowingit to easily pivot about process head pivot axis 411 with nointerference from operator arm 407, as demonstrated in FIGS. 3-5.Returning to FIG. 7, processing head housing 470 more preferably hascircumferential grooves 471 which are formed into the side of processhead housing 470. Circumferential grooves 471 have a functional benefitof increasing heat dissipation from processing head 406.

[0084] The sides of processing head housing 470 are advantageouslyprovided with rotate shaft openings 474 and 475 for receivingrespectively left and right processing head pivot shafts 429 and 430.Processing head pivot shafts 429 and 430 are secured to the processinghead 406 by respective left and right processing head mounts 472 and473. Processing head mounts 472 and 473 are affirmative connected toprocessing head frame 582 which also supports processing head door 476which is itself securely fastened to processing head housing 470.Consequently, processing head pivot shafts 429 and 430 are fixed withrespect to processing head 407 and may therefore rotate or pivot withrespect to operator arm 407. The details of how processing head pivotshafts 429 and 430 are received within operator arm 407 were discussedsupra.

[0085] Processing head housing 470 forms a processing head void 477which is used to house additional processing head components such as thespin motor, the pneumatic finger actuators, and service lines, alldiscussed more fully below.

[0086] The processing head also advantageously includes a workpieceholder and fingers for holding a workpiece, as is also more fullydescribed below.

[0087] Processing Head Spin Motor

[0088] In a large number of semiconductor manufacturing processes, isdesirable to spin the semiconductor wafer or workpiece during theprocess, for example to assure even distribution of applied processfluids across the face of the semiconductor wafer, or to aid drying ofthe wafer after a wet chemistry process. It is therefore desirable to beable to rotate the semiconductor workpiece while it is held by theprocessing head.

[0089] The semiconductor workpiece is held during the process byworkpiece holder 478 described more fully below. In order to spinworkpiece holder 478 relative to processing head 406 about spin axis479, an electric, pneumatic, or other type of spin motor or workpiecespin drive is advantageously provided.

[0090] Turning to FIG. 8, spin motor 480 has armatures 526 which drivespin motor shaft 483 in rotational movement to spin workpiece holder478. Spin motor 480 is supported by bottom motor bearing 492 in bottommotor housing 482. Bottom motor housing 482 is secured to processinghead 406 by door 476. Spin motor 480 is thus free to rotate relative toprocessing head housing 470 and door 476. Spin motor 480 is preferablyadditionally held in place by top motor housing 481 which rests onprocessing head door 476. Spin motor 480 is rotationally isolated fromtop motor housing 481 by top motor bearing 493, which is disposedbetween the spin motor shaft 483 and top motor housing 481.

[0091] The spin motor is preferably an electric motor which is providedwith an electrical supply source through pivot shaft 429 and/or 430.Spin motor 480 will drive spin motor shaft 483 about spin axis 479.

[0092] To secure workpiece holder rotor 484 to spin motor shaft 483,workpiece holder rotor 484 is preferably provided with a rotor hub 485.Rotor hub 485 defines a rotor hub recess 486 which receives a flared endof workpiece holder shaft 491. The flared end 487 of workpiece holdershaft 491 is secured within the rotor hub recess 486 by workpiece shaftsnap-ring 488 which fits within rotor recess groove 489 above the flaredportion 487 of workpiece holder shaft 491.

[0093] The workpiece holder shaft 491 is fitted inside of spin motorshaft 483 and protrudes from the top of the spin motor shaft. The top ofworkpiece holder shaft 491 is threaded to receive thin nut 527 (see FIG.7). Thin nut 527 is tightened against optical tachometer 499 (describemore fully below). Optical tachometer 499 is securely attached to spinmotor shaft 483 such that as the spin motor 480 rotationally drives thespin motor shaft 483, the workpiece holder shaft 491 is also driven.

[0094] Workpiece holders may be easily changed out to accommodatevarious configurations which may be required for the various processesencountered in manufacturing of the semiconductors. This is accomplishedby removing spin encoder 498 (described below), and then thin nut 527.Once the thin nut has been removed the workpiece holder 478 will dropaway from the processing head 406.

[0095] The processing head is also advantageously provided with a spinencoder 498, more generally described as a workpiece holder encoder, andan optical tachometer 499. As shown in FIG. 7, spin encoder 498 ismounted to top motor housing 481 by encoder support 528 so as to remainstationary with respect to the processing head 406. Optical tachometer499 is mounted on spin motor shaft 483 so as to rotate with the motor480. When operated in conjunction, the spin encoder 498 and opticaltachometer 499 allow the speed, acceleration, and precise rotationalposition of the spin motor shaft (and therefore the workpiece holder478) to be known. In this manner, and when spin motor 480 is provided asa servo motor, a high degree of control over the spin rate,acceleration, and rotational angular position of the workpiece withrespect to the process head 407 may be obtained.

[0096] In one application of the present invention the support is usedto support a semiconductor workpiece in an electroplating process. Toaccomplish the electroplating an electric current is provided to theworkpiece through an alternate embodiment of the fingers (described morefully below). To provide electric current to the finger, conductivewires are run from the tops of the fingers inside of the workpieceholder 478 through the electrode wire holes 525 in the flared lower partof workpiece holder shaft 491. The electrode wires are provided electriccurrent from electrical lines run through processing pivot shaft 429and/or 430.

[0097] The electrical line run through pivot shaft 430/429 will bynature be stationary with respect to processing head housing 470.However, since the workpiece holder rotor is intended to be capable ofrotation during the electroplating process, the wires passing intoworkpiece support shaft 491 through electrode wire holes 525 may rotatewith respect to processing head housing 470. Since the rotatingelectrode wires within workpiece shaft 491 and the stationary electricalsupply lines run through pivot shaft 430/429 must be in electricalcommunication, the rotational/stationary problem must be overcome. Inthe preferred embodiment, this is accomplished by use of electrical slipring 494.

[0098] Electrical slip ring 494, shown in FIG. 7, has a lower wirejunction 529 for receiving the conductive ends of the electrical wirespassing into workpiece holder shaft 491 by electrode wire holes 525.Lower wire junction 529 is held in place within workpiece holder shaft491 by insulating cylindrical collar 497 and thus rotates with spinmotor shaft 483. The electrode wires terminate in a single electricalcontact 531 at the top of the lower wire junction 529. Electrical slipring 494 further has a contact pad 530 which is suspended within the topof workpiece holder shaft 491. Contact pad 530 is mechanically fastenedto spin encoder 498, which, as described previously, remains stationarywith respect to processing head housing 470. Thestationary-to-rotational transition is made at the tip of contact pad530, which is in contact with the rotating electrical contact 531.Contact pad 530 is electrically conductive and is in electricalcommunication with electrical contact 531. In the preferred embodiment,contact pad 530 is made of copper-beryllium. A wire 585 carries currentto finger assemblies when current supply is needed, such as on thealternative embodiment described below.

[0099] Processing Head Finger Actuators

[0100] Workpiece holder 478, described more fully below, advantageouslyincludes fingers for holding the workpiece W in the workpiece holder, asshown in FIGS. 7 and 8. Since the workpiece holder 478 may be removed asdescribed above, it is possible to replace one style of workpiece holderwith another. Since a variety of workpiece holders with a variety offingers for holding the workpiece is possible, it is desirable to have afinger actuator mechanism disposed within processing head 407 which iscompatible with any given finger arrangement. The invention is thereforeadvantageously provided with a finger actuator mechanism.

[0101] Turning to FIG. 7, a finger actuator mechanism 500 is shown.Finger actuator mechanism 500 is preferably a pneumatically operatedmechanism. A pneumatic cylinder is formed by a cavity 501 within topmotor housing 481. Pneumatic piston 502 is disposed within cavity 501.Pneumatic piston 502 is biased in an upward position within cavity 501by actuator spring 505. Actuator spring 505 is confined within cavity501 by cavity end cap 507, which is itself constrained by retaining ring508. Pneumatic fluid is provided to the top of pneumatic piston 502 viapneumatic inlet 503. Pneumatic fluid is provided to pneumatic inlet 503by pneumatic supply line 504 which is routed through processing headpivot shaft 429 and hence through the left fork 418 of the operator arm407. Turning to FIG. 8, it can be seen that a second pneumatic cylinderwhich is identical to the pneumatic cylinder just described is alsoprovided.

[0102] Pneumatic piston 502 is attached to actuator plate 509 byactuator plate connect screw 510. Wave springs 529 provide flexibilityto the connecting at screws 510. Actuator plate 509 is preferably anannular plate concentric with the spin motor 580 and disposed about thebottom motor housing 482, and is symmetrical about spin axis 479.Actuator plate 509 is secured against pneumatic piston 502 by bushing512 which is disposed in pneumatic piston recess 511 about pneumaticpiston 502. Bushing 512 acts as a support for wave springs 529 to allowa slight tilting of the actuator plate 509. Such an arrangement isbeneficial for providing equal action against the finger actuatorcontracts 513 about the entire actuator plate or ring 509.

[0103] When pneumatic fluid is provided to the space above the pneumaticpiston 502, the pneumatic piston 502 travels in a downward directioncompressing actuator spring 505. As pneumatic piston 502 travelsdownward, actuator plate 509 is likewise pushed downward by flexiblebushing 512. Actuator plate 509 will contact finger actuator contacts513 causing the fingers to operate as more fully described below.

[0104] Actuator seals 506 are provided to prevent pneumatic gas frombypassing the top of the pneumatic piston 502 and entering the areaoccupied by actuator spring 505.

[0105] Processing Head Workpiece Holder

[0106] Workpiece holder 478 is used to hold the workpiece W, which istypically a semiconductor wafer, in position during the semiconductormanufacturing process.

[0107] Turning now to FIG. 8, a finger 409 is shown in cross section.Finger 409 advantageously includes a finger actuator contact 513 whichis contacted by actuator plate 509, as described above. Finger actuatorcontact 513 is connected to finger actuator lever 514 (more generally,“finger extension”) which is cantilevered from and connected to thefinger stem 515. Finger stem 515 is inserted into finger actuator lever514. Disposed about the portion of the finger actuator lever whichencompasses and secures finger stem 515 is finger diaphragm 519. Fingerdiaphragm 519 is preferably made of a flexible material such asTetrafluoroethylene, also known as Teflon® (registered trademark of E.I. DuPont de Nemours Company). Finger 409 is mounted to workpiece holderrotor 484 using finger diaphragm 519. Finger diaphragm 519 is insertedinto the finger opening 521 in rotor 484. The finger diaphragm 519 isinserted into the rotor from the side opposite that to which theworkpiece will be presented. Finger diaphragm 519 is secured to rotor484 against rotor diaphragm lip 523. Forces are intentionally impartedas a result of contact between the actuator plate 509 and the fingeractuator contact 513 when the finger actuator mechanism 500 is actuated.

[0108] Finger actuator lever 514 is advantageously biased in ahorizontal position by finger spring 520 which acts on finger actuatortab 522 which in turn is connected to finger actuator lever 514. Fingerspring 520 is preferably a torsion spring secured to the workpieceholder rotor 484.

[0109] Finger stem 515 is also preferably provided with finger collar ornut 517 which holds the finger stem 515 against shoulder 518. Fingercollar 517 threads or otherwise securely fits over the lower end offinger actuator lever 514. Below the finger collar 517, finger stem 515extends for a short distance and terminates in fingertip 414. Fingertip414 contains a slight groove or notch which is beneficially shaped toreceive the edge of the workpiece W.

[0110] In actuation, finger actuator plate 509 is pushed downward byfinger actuator mechanism 500. Finger actuator plate 509 continues itsdownward travel contacting finger actuator contacts 513. As actuatorplate 509 continues its downward travel, finger actuator contacts arepushed in a downward direction. As a result of the downward direction,the finger actuator levers 514 are caused to pivot.

[0111] In the preferred embodiment, a plurality of fingers are used tohold the workpiece. In one example, six fingers were used. Once theactuator plate 509 has traveled its full extent, the finger stems 515will be tilted away from the spin axis 479. The circumference describedby the fingertips in this spread-apart position should be greater thanthe circumference of the workpiece W. Once a workpiece W has beenpositioned proximate to the fingertips, the pneumatic pressure isrelieved on the finger actuator and the actuator spring 505 causes thepneumatic piston 502 to return to the top of the cavity 501. In sodoing, the actuator plate 509 is retracted and the finger actuatorlevers are returned to their initial position by virtue of fingersprings 520.

[0112] Semiconductor Workpiece Holder—Electroplating Embodiment

[0113]FIG. 15 is a side elevational view of a semiconductor workpieceholder 810 constructed according to a preferred aspect of the invention.

[0114] Workpiece holder 810 is used for processing a semiconductorworkpiece such as a semiconductor wafer shown in phantom at W. Onepreferred type of processing undertaken with workpiece holder 810 is aworkpiece electroplating process in which a semiconductor workpiece isheld by workpiece holder 810 and an electrical potential is applied tothe workpiece to enable plating material to be plated thereon. Such canbe, and preferably is accomplished utilizing a processing enclosure orchamber which includes a bottom half or bowl 811 shown in phantom linesin FIG. 1. Bottom half 811 together with workpiece holder 810 forms asealed, protected chamber for semiconductor workpiece processing.Accordingly, preferred reactants can be introduced into the chamber forfurther processing. Another preferred aspect of workpiece holder 810 isthat such moves, rotates or otherwise spins the held workpiece duringprocessing as will be described in more detail below.

[0115] Processing Head and Processing Head Operator

[0116] Turning now to FIG. 15, semiconductor workpiece holder 810includes a workpiece support 812. Workpiece support 812 advantageouslysupports a workpiece during processing. Workpiece support 812 includes aprocessing head or spin head assembly 814. Workpiece support 812 alsoincludes a head operator or lift/rotate assembly 816. Spin head assembly814 is operatively coupled with lift/rotate assembly 816. Spin headassembly 814 advantageously enables a held workpiece to be spun or movedabout a defined axis during processing. Such enhances conformal coverageof the preferred plating material over the held workpiece. Lift/rotateassembly 816 advantageously lifts spin head assembly 814 out ofengagement with the bottom half 811 of the enclosure in which thepreferred processing takes place. Such lifting is preferably about anaxis x₁. Once so lifted, lift/rotate assembly 816 also rotates the spinhead and held workpiece about an axis x₂ so that the workpiece can bepresented face-up and easily removed from workpiece support 812. In theillustrated and preferred embodiment, such rotation is about 180° fromthe disposition shown in FIG. 15. Advantageously, a new workpiece can befixed or otherwise attached to the workpiece holder for furtherprocessing as described in detail below.

[0117] The workpiece can be removed from or fixed to workpiece holder810 automatically by means of a robotically controlled arm.Alternatively, the workpiece can be manually removed from or fixed toworkpiece holder 810. Additionally, more than one workpiece holder canbe provided to support processing of multiple semiconductor workpieces.Other means of removing and fixing a semiconductor workpiece arepossible.

[0118]FIG. 16 is a front sectional view of the FIG. 15 semiconductorworkpiece holder. As shown, workpiece support 812 includes a motor 818which is operatively coupled with a rotor 820. Rotor 820 isadvantageously mounted for rotation about a rotor spin axis 822 andserves as a staging platform upon which at least one finger assembly 824is mounted. Preferably, more than one finger assembly is mounted onrotor 820, and even more preferably, four or more such finger assembliesare mounted thereon and described in detail below although only two areshown in FIG. 16. The preferred finger assemblies are instrumental infixing or otherwise holding a semiconductor workpiece on semiconductorworkpiece holder 810. Each finger assembly is advantageously operativelyconnected or associated with a actuator 825. The actuator is preferablya pneumatic linkage which serves to assist in moving the fingerassemblies between a disengaged position in which a workpiece may beremoved from or added to the workpiece holding, and an engaged positionin which the workpiece is fixed upon the workpiece holder forprocessing. Such is described in more detail below.

[0119]FIG. 17 is a top or plan view of rotor 820 which is effectivelytaken along line 3-3 in FIG. 16. FIG. 16 shows the preferred four fingerassemblies 824. As shown, rotor 820 is generally circular and resemblesfrom the top a spoked wheel with a nearly continuous bottom surface.Rotor 820 includes a rotor center piece 826 at the center of which liesrotor axis 822. A plurality of struts or spokes 828 are joined orconnected to rotor center 826 and extend outwardly to join with andsupport a rotor perimeter piece 830. Advantageously, four of spokes 828support respective preferred finger assemblies 824. Finger assemblies824 are advantageously positioned to engage a semiconductor workpiece,such as a wafer W which is shown in phantom lines in the position suchwould occupy during processing. When a workpiece is so engaged, it isfixedly held in place relative to the rotor so that processing can beeffected. Such processing can include exposing the workpiece toprocessing conditions which are effective to form a layer of material onone or more surfaces or potions of a wafer or other workpiece. Suchprocessing can also include moving the workpiece within a processingenvironment to enhance or improve conformal coverage of a layeringmaterial. Such processing can, and preferably does include exposing theworkpiece to processing conditions which are effective to form anelectroplated layer on or over the workpiece.

[0120] Finger Assembly

[0121] Referring now to FIGS. 18-20, various views of a preferred fingerassembly are shown. The preferred individual finger assemblies areconstructed in accordance with the description below. FIG. 18 is anisolated side sectional view of a finger assembly constructed inaccordance with a preferred aspect of the invention. FIG. 19 is a sideelevational view of the finger assembly turned 90° from the view of FIG.18. FIG. 20 is a fragmentary cross-sectional enlarged view of a fingerassembly and associated rotor structure. The finger assembly as setforth in FIGS. 18 and 19 is shown in the relative position such as itwould occupy when processing head or spin head assembly 814 (FIGS. 15and 16) is moved or rotated by head operator or lift/rotate assembly 816into a position for receiving a semiconductor workpiece. The fingerassembly is shown in FIGS. 18 and 20 in an orientation of about 180°from the position shown in FIG. 20. This typically varies because spinhead assembly 814 is rotated 180° from the position shown in FIGS. 15and 16 in order to receive a semiconductor workpiece. Accordingly,finger assemblies 824 would be so rotated. Lesser degrees of rotationare possible.

[0122] Finger assembly 824 includes a finger assembly frame 832.Preferably, finger assembly frame 832 is provided in the form of asealed contact sleeve which includes an angled slot 832 a, only aportion of which is shown in FIG. 19. Angled slot 832 a advantageouslyenables the finger assembly to be moved, preferably pneumatically, bothlongitudinally and rotationally as will be explained below. Suchpreferred movement enables a semiconductor workpiece to be engaged,electrically contacted, and processed in accordance with the invention.

[0123] Finger assembly frame 832 includes a finger assembly frame outerflange 834 which, as shown in FIG. 20, engages an inner drive plateportion 836 of rotor 820. Such engagement advantageously fixes or seatsfinger assembly frame 832 relative to rotor 820. Such, in turn, enablesthe finger assembly, or a portion thereof, to be moved relative to therotor for engaging the semiconductor workpiece.

[0124] Finger Assembly Drive System

[0125] Referring to FIGS. 16 and 18-20, the finger assembly includes afinger assembly drive system which is utilized to move the fingerassembly between engaged and disengaged positions. The finger assemblydrive system includes a bearing 838 and a collet 840 operativelyadjacent the bearing. Bearing 838 includes a bearing receptacle 839 forreceiving a pneumatically driven source, a fragmented portion of whichis shown directly above the receptacle in FIG. 20. The pneumaticallydriven source serves to longitudinally reciprocate and rotate collet840, and hence a preferred portion of finger assembly 824. A preferredpneumatically driven source is described below in more detail inconnection with the preferred longitudinal and rotational movementeffectuated thereby. Such longitudinal reciprocation is affected by abiasing mechanism in the form of a spring 842 which is operativelymounted between finger assembly frame 832 and a spring seat 844. Theconstruction develop a bias between finger assembly frame 832 and springseat 844 to bias the finger into engagement against a wafer.Advantageously, the cooperation between the above mentionedpneumatically driven source as affected by the biasing mechanism of thefinger assembly drive system, enable collet 840 to be longitudinallyreciprocated in both extending and retracting modes of movement. Assuch, finger assembly 824 includes a biased portion which is biasedtoward a first position and which is movable to a second position awayfrom the first position. Other manners of longitudinally reciprocatingthe finger assembly are possible.

[0126] Finger Assembly Electrical System

[0127] Referring to FIGS. 16 and 19, the finger assembly preferablyincludes a finger assembly electrical system which is utilized toeffectuate an electrical bias to a held workpiece and supply electricalcurrent relative thereto. The finger assembly electrical system includesa pin connector 846 and a finger 848. Pin connector 846 advantageouslyprovides an electrical connection to a power source (not shown) via wire585 and associate slip ring mechanism, described above in connectionwith FIG. 7 and other Figs. This is for delivering an electrical biasand current to an electrode which is described below. Pin connector 846also rides within angled slot 832 a thereby mechanically defining thelimits to which the finger assembly may be both longitudinally androtationally moved.

[0128] Finger 848 is advantageously fixed or secured to or within collet840 by a nut 850 which threadably engages a distal end portion of collet840 as shown best in FIG. 18. An anti-rotation pin 852 advantageouslysecures finger 848 within collet 840 and prevents relative rotationtherebetween. Electrical current is conducted from connector 846 throughcollet 840 to finger 860, all of which are conductive, such as fromstainless steel. The finger and collet can be coated with a suitabledielectric coating 856, such as TEFLON or others. The collet 840 andfinger member 860 are in one form of the invention made hollow andtubular to conduct a purge gas therethrough.

[0129] Finger assembly 824 may also optionally include a distal tip orfinger tip 854. Tip 854 may also have a purge gas passage formedtherethrough. Finger tip 854 advantageously engages against asemiconductor workpiece (see FIG. 20) and assists in holding or fixingthe position of the workpiece relative to workpiece holder 810. Fingertip 854 also assists in providing an operative electrical connectionbetween the finger assembly and a workpiece to which an electricalbiased is to be applied and through which current can move. Finger tip85 can include an electrode contact 858 for electrically contacting asurface of a semiconductor workpiece once such workpiece is secured asdescribe below.

[0130] Finger Assembly Drive System Interface

[0131] A finger assembly drive system interface is operatively coupledwith the finger assembly drive system to effectuate movement of thefinger assembly between the engaged and disengaged positions. Apreferred finger assembly drive system interface is described withreference to FIGS. 16 and 20. One component of the finger assembly drivesystem interface is a finger actuator 862. Finger actuator 862 isadvantageously provided for moving the finger assembly between theengaged and disengaged position. Finger actuator 862 acts by engagingbearing receptacle 839 and moving finger assembly 824 between an engagedposition and a disengaged position. In the engaged position, finger tip854 is engaged against a semiconductor workpiece. In the disengagedposition finger tip 854 is moved away from the workpiece.

[0132] The finger assembly drive system interface includes pneumaticactuator 825 (FIG. 16). Pneumatic actuators 825 are operativelyconnected to an actuation ring 863 and operates thereupon causing thedrive plate to move reciprocally in the vertical direction as viewed inFIG. 16. Finger actuator 862 is operatively connected to actuation ring863 in a manner which, upon pneumatic actuation, moves the fingeractuator into engagement with bearing receptacle 839 along the dashedline in FIG. 20. Such allows or enables the finger assembly to be movedlongitudinally along a first movement path axis 864.

[0133] Pneumatic actuator linkage 825 also includes a secondary linkage865. Secondary linkage 865 is pneumatic as well and includes a link arm867. Link arm 867 is connected or joined to an actuator torque ring 869.Preferably, torque ring 869 is concentric with rotor 820 (FIG. 17) andcircuitously links each of the finger actuators together. A pneumaticoperator 871 is advantageously linked with the secondary linkage 865 forapplying force and operating the linkage by angularly displacing torquering 869. This in turn rotates the finger assemblies into and away fromthe engaged position.

[0134] Preferably finger actuator engagement bits 862, under theinfluence of pneumatic linkage 825, moves the finger assembly, and morespecifically collet 840 and finger 848 along a first axial movement pathalong axis 864. The finger actuator engagement bits 862, then under theinfluence of pneumatic operator 871 are turned about the axes of eachbit like a screwdriver. This moves collet 840 and finger 848 in a secondangular movement. Such second movement turns the fingers sufficiently toproduce the angular displacement shown in FIG. 21. According to apreferred aspect of this invention, such movement of the fingerassemblies between the engaged and disengaged positions takes place whenspin head assembly 814 has been moved 180° from its FIG. 15 dispositioninto a face-up condition.

[0135] The engagement bits 862 can be provided with a purge gas passagetherethrough. Gas is supplied via tube 893 and is passed through thefinger assemblies.

[0136] Engaged and Disengaged Positions

[0137]FIG. 21 is a view of a portion of a finger assembly, taken alongline 7-7 in FIG. 18. Such shows in more detail the above-describedengaged and disengaged positions and movement therebetween relative to aworkpiece W. In the disengaged position, finger 848 is positionedadjacent the semiconductor workpiece and the finger tip and electrodecontact do not overlap with workpiece W. In the engaged position, thefinger tip overlaps with the workpiece and the electrode is brought tobear against the workpiece. From the disengaged position, fingerassembly 824, upon the preferred actuation, is moved in a firstdirection away from the disengaged position. Preferably, such firstdirection is longitudinal and along first movement path axis 864. Suchlongitudinal movement is linear and in the direction of arrow A as shownin FIGS. 18 and 19. The movement moves the finger assembly to theposition shown in dashed lines in FIG. 18. Such movement is effectuatedby pneumatic operator 825 which operates upon actuation ring 863 (FIG.16). This in turn, causes finger actuator 862 to engage with fingerassembly 824. Such linear movement is limited by angled slot 832 a.Thereafter, the finger assembly is preferably moved in a seconddirection which is different from the first direction and preferablyrotational about the first movement path axis 864. Such is illustratedin FIG. 21 where the second direction defines a generally arcuate pathbetween the engaged and disengaged positions. Such rotational movementis effectuated by secondary linkage 865 which pneumatically engages thefinger actuator to effect rotation thereof. As so moved, the fingerassembly swings into a ready position in which a semiconductor workpieceis ready to be engaged and held for processing. Once the finger assemblyis moved or swung into place overlapping a workpiece, the preferredfinger actuator is spring biased and released to bear against theworkpiece. An engaged workpiece is shown in FIG. 20 after the workpiecehas been engaged by finger tip 854 against a workpiece standoff 865, andspin head assembly 814 has been rotated back into the position shown inFIG. 15. Such preferred pneumatically assisted engagement takes placepreferably along movement path axis 864 and in a direction which is intothe plane of the page upon which FIG. 21 appears.

[0138] As shown in FIG. 18, finger 848 extends away from collet 840 andpreferably includes a bend 866 between collet 840 and finger tip 854.The preferred bend is a reverse bend of around 180° which serves topoint finger tip 854 toward workpiece W when the finger assembly ismoved toward or into the engaged position (FIG. 21). Advantageously, thecollet 840 and hence finger 848 are longitudinally reciprocally movableinto and out of the engaged position.

[0139] Finger Assembly Seal

[0140] The finger assembly preferably includes a finger assembly seal868 which is effectuated between finger 848 and a desired workpiece whenthe finger assembly is moved into the engaged position. Preferably,adjacent finger tip 854. A seal 868 is mounted adjacent electrodecontact 858 and effectively seals the electrode contact therewithin whenfinger assembly 824 is moved to engage a workpiece. The seal can be madeof a suitable flexible, preferably elastomeric material, such as VITON.

[0141] More specifically, and referring to FIG. 22, seal 868 can includea rim portion 870 which engages workpiece surface W and forms a sealingcontact therebetween when the finger assembly is moved to the engagedposition. Such seal advantageously isolates finger electrode 860 fromthe processing environment and materials which may plate out orotherwise be encountered therein. Seal 868 can be provided with anoptional bellows wall structure 894 (FIG. 22), that allows more axialflexibility of the seal.

[0142]FIG. 22 shows, in solid lines, seal 868 in a disengaged positionin which rim portion 870 is not engaged with workpiece W. FIG. 22 alsoshows, in phantom lines, an engaged position in which rim portion 870 isengaged with and forms a seal relative to workpiece W. Preferably andadvantageously, electrode contact 858 is maintained in a generallyretracted position within seal 868 when the finger assembly is in thedisengaged position. However, when the finger assembly is moved into theengaged position, seal 868 and rim portion 870 thereof splay outwardlyor otherwise yieldably deform to effectively enable the electrode andhence electrode contact 858 to move into the engaged position againstthe workpiece. One factor which assists in forming the preferred sealbetween the rim portion and the workpiece is the force which isdeveloped by spring 842 which advantageously urges collet 840 and hencefinger 860 and finger tip 858 in the direction of and against thecaptured workpiece. Such developed force assists in maintaining theintegrity of the seal which is developed in the engaged position.Another factor which assists in forming the preferred seal is theyieldability or deformability of the finger tip when it is brought intocontact with the workpiece. Such factors effectively create a continuousseal about the periphery of electrode contact 858 thereby protecting itfrom any materials, such as the preferred plating materials which areused during electroplate processing.

[0143] Methods and Operation

[0144] In accordance with a preferred processing aspect of the presentinvention, and in connection with the above-described semiconductorworkpiece holder, a sheathed electrode, such as electrode 860, ispositioned against a semiconductor workpiece surface in a manner whichpermits the electrode to impart a voltage bias and current flow to theworkpiece to effectuate preferred electroplating processing of theworkpiece. Such positioning not only allows a desired electrical bias tobe imparted to a held workpiece, but also allows the workpiece itself tobe mechanically held or fixed relative to the workpiece holder. That is,finger assembly 824 provides an electrical/mechanical connection betweena workpiece and the workpiece holder as is discussed in more detailbelow.

[0145] Electrode 856 includes an electrode tip or electrode contact 858which engages the workpiece surface. A seal is thus formed about theperiphery of the electrode tip or contact 858 so that a desiredelectrical bias may be imparted to the workpiece to enable platingmaterial to be plated thereon. According to a preferred aspect of theprocessing method, the electrode is moved in a first direction,preferably longitudinally along a movement axis, away from a disengagedposition in which the workpiece surface is not engaged by the electrodetip or contact 858. Subsequently, the electrode is rotated about thesame movement axis and toward an engaged position in which the electrodetip may engage, so as to fix, and thereafter bias the workpiece surface.Such preferred movement is effectuated by pneumatic linkage 825 andpneumatic operator 871 as described above.

[0146] According to a preferred aspect of the invention, the seal whichis effectuated between the electrode member and the workpiece is formedby utilizing a yieldable, deformable seal member 868 which includes arim portion 870. The rim portion 870 serves by contacting the workpiecesurface to form a continuous seal as shown in FIG. 8. The preferredelectrode tip is brought into engagement with the workpiece surface byadvancing the electrode tip from a retracted position within the seal orother sheath to an unretracted position in which the workpiece surfaceis engaged thereby. Such movement of the electrode tip between theretracted and unretracted positions is advantageously accommodated bythe yieldable features of the seal 868.

[0147] In addition to providing the preferred electrical contact betweenthe workpiece and the electrode tip, the finger assembly also forms amechanical contact or connection between the assembly and the workpiecewhich effectively fixes the workpiece relative to the workpiece holder.Such is advantageous because one aspect of the preferred processingmethod includes rotating the workpiece about rotor axis 822 while theworkpiece is exposed to the preferred plating material. Such not onlyensures that the electrical connection and hence the electrical biasrelative to the workpiece is maintained during processing, but that themechanical fixation of the workpiece on the workpiece holder ismaintained as well.

[0148] The above described pneumatically effectuated movement of thepreferred finger assemblies between the engaged and disengaged positionsis but one manner of effectuating such movement. Other manners ofeffectuating such movement are possible.

[0149] The invention also includes novel methods for presenting aworkpiece to a semiconductor process. In such methods, a workpiece isfirst secured to a workpiece holder. The methods work equally well forworkpiece holders known in the art and for the novel workpiece holdersdisclosed herein.

[0150] In the next step in the sequence, the workpiece holder is rotatedabout a horizontal axis from an initial or first position where theworkpiece holder was provided with the workpiece to a second position.The second position will be at an angle to the horizontal. The angle ofthe workpiece holder to the horizontal is defined by the angle betweenthe plane of the workpiece and the horizontal. In the method, theworkpiece holder is advantageously suspended about a second horizontalaxis which is parallel to the first horizontal axis of the workpieceholder. At this point in the method, the angle between the first andsecond horizontal axes and a horizontal plane corresponds to the anglebetween the workpiece holder and the horizontal. The workpiece holder isthen pivoted about the second horizontal axis to move the workpiece andthe workpiece holder from its initial location to a final location in ahorizontal plane. Advantageously, when the workpiece holder is pivotedabout the second horizontal axis, the first horizontal axis also pivotsabout the second horizontal axis.

[0151] Preferably, during the step of rotating the workpiece holderabout the first horizontal axis, the angle of the workpiece holder withrespect to some known point, which is fixed with respect to theworkpiece holder during the rotation process, is continually monitored.Monitoring allows for precise positioning of the workpiece holder withrespect to the horizontal surface.

[0152] Likewise, during pivoting of the workpiece holder about thesecond horizontal axis, it is preferable that the angle defined by theline connecting the first and second horizontal axes and the horizontalplane be continually monitored. In this manner, the absolute position ofthe workpiece holder (and hence the workpiece itself) will be known withrespect to the horizontal plane. This is important since the horizontalplane typically will contain the process to which the workpiece will beexposed.

[0153] It should be noted that in the above and following description,while the workpiece is described as being presented to a horizontalplane, it is possible that the workpiece may also be presented to avertical plane or a plane at any angle between the vertical and thehorizontal. Typically, the processing plane will be a horizontal planedue to the desire to avoid gravitational effects on process fluids towhich the workpiece is exposed. In one embodiment after the workpiecehas been presented to the processing plane, the workpiece holder isrotated about a spin axis to cause the workpiece to spin in thehorizontal plane. Although not required in all semiconductormanufacturing processes, this is a common step which may be added in theappropriate circumstance.

[0154] The next advantageous step tin the method consists of pivotingthe workpiece holder about the second horizontal axis back along thepath that the workpiece holder was initially pivoted along whenpresenting the workpiece to the horizontal process plane. There is norequirement that the workpiece holder be pivoted back to the sameposition whence it began, although doing so may have certain advantagesas more fully described below.

[0155] The method advantageously further consists of the step ofrotating the workpiece holder about the first horizontal axis to returnthe workpiece to the position when it was initially presented to andengaged by the workpiece holder. It is advantageous to rotate theworkpiece holder about the first axis in a direction opposite from theinitial rotation of the workpiece holder.

[0156] The advantage of having the workpiece holder terminate at an endposition which corresponds to the initial position when the workpiecewas loaded into the workpiece holder is efficiency. That is, additionalmachine movements are not required to position the workpiece holder toreceive a new workpiece.

[0157] The method more preferably includes the step of rotating theworkpiece holder about the first horizontal axis at least two supportpoints along the first horizontal axis. This beneficially providessupport and stability to the workpiece holder during the rotationprocess and subsequent movement of the apparatus.

[0158] The method also more preferably includes the step of pivoting theworkpiece holder along with the first horizontal axis about the secondhorizontal axis at least two support points along the second horizontalaxis. This beneficially provides additional support for the workpieceholder while allowing the workpiece holder to be moved in a vertical or“Z-axis” direction.

[0159] Importantly, the only motion described in the above method isrotational motion about several axes. In the method described, there isno translational motion of the workpiece holder in a X-, Y-, or Z-axiswithout corresponding movement in another axis as a result of rotatingthrough an arc.

[0160] Second Embodiment Processing Station—Generally

[0161]FIG. 23 shows principal components of a second semiconductorprocessing station 900 incorporating features of the invention.Processing station 900 as shown is specifically adapted and constructedto serve as an electroplating station similar to electroplating station400 described hereinabove. To reduce unnecessary replication, only theprincipal parts showing differences and features of the invention areshown and described. Other aspects of the invention are as describedabove or can be done in a variety of constructions.

[0162] The two principal parts of processing station 900 are theworkpiece support assembly 901 and the processing bowl 917. Theworkpiece support 401 will be considered first and the processing bowland its features will be described in further detail later in thisdescription. As FIG. 23 indicates, portions of the workpiece support 401mate with the processing bowl to provide a substantially closedprocessing vessel which encloses a substantially enclosed processing ormanufacturing chamber 904.

[0163] Workpiece Support Generally

[0164] The workpiece support processing head holds a wafer W forrotation within the processing chamber 904. A rotor assembly 984 has aplurality of workpiece-engaging fingers 979 that hold the wafer againstfeatures of the rotor. Fingers 979 are also preferably adapted toconduct current between the wafer and a plating electrical power supply(not shown).

[0165] Workpiece Support Head Operator

[0166] The workpiece support assembly 901 includes a processing head 906which is supported by an head operator 907. Head operator 907 includesan upper portion 908 which is adjustable in elevation to allow heightadjustment of the processing head. Head operator 907 also has a headconnection shaft 909 which is operable to pivot about a horizontal pivotaxis 910. Pivotal action of the processing head using operator 907allows the processing head to be placed in an open or face-up position(not shown) for loading and unloading wafer W. FIG. 23 shows theprocessing head pivoted into a face-down position in preparation forprocessing.

[0167] A variety of suitable head operators which provide bothelevational and horizontal pivoting action are possible for use in thissystem. The preferred operators are also fitted with positional encoders(not shown) which indicate both the elevation of the processing head andits angular position as pivoted about horizontal head pivot axis 910.

[0168] Workpiece Support Main Part

[0169]FIGS. 24 and 25 show additional details of the preferredconstruction of processing head 906. The processing head includes a mainpart which moves with and is relatively stationary with respect to thepivot shaft 909. The main part supports a rotating assembly which willbe described in greater detail below.

[0170] The main part includes a processing head housing 970 andprocessing head frame 982. The processing head frame 982 includes a doorplate 983. A door ring member 984 is joined to plate 983 using suitablefasteners to provide a door assembly which serve as the principal partscovering the upper opening of the processing bowl when the processinghead is mated with the bowl.

[0171] The processing head frame also includes a frame-pivot shaftconnection 985 which includes two mounting rings which receive andsecurely connect with the processing head pivot shaft 909. FIG. 25 showsthat the pivot shaft connection mounting rings are made in two parts andsecured by fasteners (not shown). The pivot shaft connection base 935 issecured to the door plate 983 using fasteners.

[0172] Processing head 906 is generally round in shape when viewed inplan view. The processing head main part includes a housing 970 whichhas a first housing part 971 and a second housing part or housing cap972. The processing head housing 970 encloses a main part enclosurewhich surrounds a processing head main part mechanism chamber 973.Chamber 973 is used to house additional processing head components, suchas the spin motor, the finger actuators, and related service lines, suchas discussed more fully below.

[0173] The upper surface of the door ring member 984 is provided with agroove which receives the lower edge of the first housing piece 971. Theouter periphery of the door ring member also advantageously includes aperipheral groove 986 which mounts an inflatable door seal 987. Seal 987seals with portions of the processing bowl to form a more fluid-tightprocessing chamber therewithin.

[0174] The lower surface of the door ring member 984 is preferablyprovided with an annular rotor receiving groove 988 which receives topperipheral portions of the rotor therein in close proximity. Thisconstruction allows a gas purge (not shown) to be applied between thedoor and rotor to help prevent processing vapors from migrating behindthe rotor and into to the various mechanisms present in the main part ofthe processing head. The periphery of the door ring member is furtherprovided with a chamfered lower edge to facilitate mating with theprocessing bowl.

[0175] The processing head also advantageously includes a movingassembly in the form of a workpiece holder 978. The workpiece holderincludes fingers 979 for holding a semiconductor workpiece. Thesefeatures will be more fully described below.

[0176] Workpiece Support Rotor Drive

[0177] The processing head main part also includes a workpiece holderdrive which moves the workpiece holder relative to the main part of theprocessing head. The preferred action is for the workpiece holder driveto be in the form of a rotor drive which rotates the workpiece holder.The rotor drive can be an electric motor, pneumatic motor or othersuitable drive. As shown, the processing head includes an electricworkpiece spin motor 980.

[0178] The drive motor 980 has stator armatures 916 which drive motorshaft 918 in rotational movement. Drive motor 980 is supported by bottommotor bearing 921 in bottom motor housing 922. Bottom motor housing 922is secured to the main part of the processing head at a central openingin the door plate 983. Motor 980 is also held in place by a top motorhousing 923. Drive motor 980 is rotationally isolated from top motorhousing 923 by a top motor bearing 927, which is disposed between thespin motor shaft 918 and the top motor housing. Both motor housings aresecured to the processing head frame 982 using fasteners 924 whichextend down through the motor housings and into the door plate 983. Thefasteners 924 also extend upwardly through frame extensions 925. Frameextensions 925 support a top frame piece 926. Cap 972 is screwed ontopiece 926 at mating threads along the lower interior portion of the cap.

[0179] The drive motor is preferably an electric motor provided with asupply of electricity via wiring run through pivot shaft 909 orotherwise extending to the processing head.

[0180] Workpiece Support Rotor Assembly

[0181] The hollow shaft 918 of the drive motor receives portion of arotor assembly therein. The rotor assembly is secured to the motor shaftand is rotated therewith. FIG. 26 shows major portions of the rotorassembly in exploded detail. The rotor assembly 930 includes a rotorshaft 931. Rotor shaft 931 has a rotor shaft hub 932 which is heldwithin a shaft hub receptacle 933 formed in an inner rotor part 934. Theinner or first rotor part 934, also called an inner rotor drive plate,has a plurality of spokes which extend from the inner rotor part hub 935outwardly to connect with a peripheral band 936. The shaft hub 932 isheld in the hub receptacle 933 using a snap-ring 937.

[0182] The inner rotor part 934 also includes a plurality of receptacles937. Receptacles 937 are used to mount a plurality of actuatortransmission assemblies 960. The transmission receptacles 937 receivelower portions of the transmission assemblies. The receptacles havebottom openings through which the finger assemblies 979 (see FIG. 24)extend and are mounted in the transmission assemblies. Additionaldescription is provided below in connection with the finger assemblyactuators.

[0183]FIG. 26 also shows that the rotor assembly 930 preferably includesa second or outer rotor part 940. The inner and outer rotor parts aresecured together by fasteners 941 (see FIG. 24). The outer rotor part940 includes a rotor face panel 943 which extends across the disk-shapedrotor part to form a barrier to processing fluids.

[0184] The front or exposed side of the outer rotor part is providedwith apertures 787 through which finger actuator transmission shafts 963extend in supporting relationship for the fingers 979. Workpiece supportstandoffs 721 are mounted upon the face of the rotor to support the backside of the workpieces in opposition to the forces exerted by thefingers 979. The face of the rotor can also advantageously be providedwith workpiece peripheral guide pins 722 to facilitate proper locationof a wafer upon installation upon the face of the rotor.

[0185] Along the back side of the outer rotor part are reinforcing ribs942 which align with the spokes of the inner rotor part 934. Thereinforcing ribs 942 receive fasteners 941 and connect the two rotorparts together. At the periphery of the outer rotor part is a side wall944. The upper or back edge of the peripheral side wall 944 is in closefitting relationship with the door ring 984 at annular groove 988 toresist migration of processing fluids to the back side of the rotorassembly.

[0186] The outer rotor part 940 also has an array of bosses 948 at theperipheral end of the reinforcing ribs 942. Within bosses 948 are fingerpassageways 949 which allow the finger assemblies 979 to mount in thefinger actuator transmission assemblies 960. The rotor assembly alsoincludes the transmission assemblies and finger assemblies. Additionaldetails of these components as well as additional parts of the fingeractuation mechanisms is described in greater detail below.

[0187] The rotor shaft 931 fits inside of motor shaft 918 and protrudesfrom the top of the shaft and is held by a rotor shaft mounting nut 888.Also mounted near the top of the rotor shaft is an optical tachometer499. Optical tachometer 499 is securely attached to motor shaft 918 andfeatures, such as notches, formed on the tachometer are opticallydetected to provide a precise measurement of rotor angular velocity. Theoptical emitter-detector couplet used with tachometer 499 are not shown,but are mounted on either sides of the wheel to allow selective passageof light therethrough.

[0188] The rotor assembly is also advantageously provided with a angularposition encoder 498. As shown, encoder 498 is mounted to the top motorhousing 923 so as to remain stationary with respect to the main part ofthe processing head. The angular position encoder 498 and opticaltachometer 499 allow the speed, acceleration, and precise rotationalposition of the motor shaft 918 and rotor assembly to be known andcontrolled.

[0189] In one application of the present invention the workpiece supportis used to support a semiconductor workpiece in an electroplatingprocess. To accomplish the electroplating an electric current isprovided to the workpiece through an alternate embodiment of the fingers(described more fully below). To provide electric current to theelectrode fingers 979, conductive wires (not shown) are run from thetransmissions 960 toward the hub of the rotor. Current is supplied tothe electrode fingers 979 through the hollow rotor shaft using wires(not shown) connected to a slip ring electrical connector 687 mountednear the upper end of shafts 918 and 931.

[0190] Workpiece Detection Subsystem

[0191] The processing head also preferably includes a wafer or workpiecedetection subsystem. This subsystem allows the processing head tothrough its control system to determine whether there is a workpieceheld in the rotor or not. This is of particular significance if thesystem experiences a power interruption or otherwise is being started inany situation where workpieces may be present in the machine.Operational safeguards can then be included in the control system toprevent mishandling of wafers or processing stations which may have aworkpiece held therein.

[0192] As shown in FIG. 25, the processing head frame part 983 isprovided with a mounting 738 which is an appropriately shaped recessused to mount a detector 739. Detector 739 is preferably an opticalemitter-detector unit which emits a beam which passes downwardly asoriented in FIG. 25. The emitted beam passes through workpiece detectorwindows 741 (see FIG. 26) formed in the face panel of the outer rotorpart. The windows can be discrete inserts, or more preferably, they arethinly dimensioned panel portions of the rotor face panel 943. The rotorface panel is advantageously made of a material which is transmissive ofthe detector beam being used. For example, the panel can be made frompolyvinylidene fluoride polymer which is thinned to a suitably thindimension, such as in the approximate range from about 1-5 millimeters.

[0193] A suitable detector 739 is a Sunx brand model RX-LS200, and othercommercially available detectors. The preferred detector uses aninfrared beam emitter (not individually shown) which is detected by apair of beam detectors (not individually shown). The beam emitter andbeam detectors are preferably part of the same unit which serves as theworkpiece detector. The workpiece detector preferably operated in atrigonometric mode. In the trigonometric mode, the angle of thereflected beam is an important discriminating parameter. Thus anyportion of the beam reflected by the detector window 741 is incidentupon the pair of detectors at a reflection angle which is outside of thenormal detection angle range. Such portions of the beam reflected by thewindow 741 are thus minimized and the detector is not triggered by suchreflectance. Instead, the pair of beam detectors are adjusted to sense areflected beam which is incident at a reflected angle associated withthe wafer or other workpiece surface which is more distant than thewindow. When there is no workpiece held in the workpiece holder, thenthe detector senses the absence and this is used by the control systemas an indication that there is no wafer present in the wafer support.

[0194] In general the emitted infrared beam used in the preferredworkpiece detector subsystem is sufficient to detect the presence of awafer or other semiconductor workpiece held in a stationary positionwith the rotor positioned so that one of the windows 741 is in positionaligned to allow the emitted beam to pass therethrough and be reflectedby the workpiece back through the window for detection. The detectionsystem described herein is not sufficient to allow detection duringrotation of the rotor and any workpiece held thereon. The invention mayalso be practiced in a situation where sensing can be accomplished whilethe rotor rotates.

[0195] The workpiece detector arrangement shown has the distinct benefitof being mounted wholly behind the rotor face panel without provision ofany openings which might allow processing fluids to enter the spacebehind the rotor. This reduces maintenance, improves reliability, andsimplifies construction costs.

[0196] Workpiece Support Finger Actuator

[0197] The preferred wafer support also includes a plurality ofwafer-engaging fingers 979 positioned about the periphery of the waferor other workpiece. FIG. 27 shows the front face of the outer rotor part940 in a face-up orientation with fingers 979 extending therefrom. Thepreferred fingers are J-shaped and mounted for pivotal action about afinger pivot axes 953. The pivotal action preferably ranges between anoutboard position and an inboard position. In the outboard position theJ-shaped fingers are positioned outwardly and clear of the waferperipheral edge. A preferred outboard position is illustrated in FIG.27. In the outboard position the hooked portions of the J-shaped fingersare oriented at approximately 15 angular degrees outward from a linedrawn tangent to the periphery of the wafer adjacent to the finger. Inthe inboard position the fingers are positioned inwardly to engage thewafer, as shown in FIG. 28. In the inboard position the hooked portionsof the J-shaped fingers are oriented at approximately 45 angular degreesinward from a line drawn tangent to the periphery of the wafer adjacentto the finger.

[0198] The face of the rotor assembly is provided with workpiecestandoff supports 721 which are in complementary position to theengagement ends of the fingers when the fingers are in a retractedposition to hold the wafer. This construction securely captures thewafer or other workpiece between the fingers and the standoffs.

[0199] In addition to the pivotal action of the engagement fingers, thefingers are also move axially toward and away from the face of therotor. In the inboard position the fingers are retracted toward thewafer to engage the exposed, front face of the wafer along a marginalband adjacent to the periphery of the wafer. In the outboard positionthe fingers are extended away from the face of the wafer to preventrubbing action as the fingers pivot away from the wafer. This compoundaction including both a pivot component and an axial component isaccomplished using a finger actuator transmission 960 shown inperspective relationship to the rotor in FIG. 26. Transmissions 960 aremounted within the transmission receptacles 937 of the inner rotor part934. The transmissions are further mounted by transmission retainers 951which are secured by fasteners to inner rotor part 934.

[0200]FIG. 29 shows the finger actuator transmission 960 in greaterdetail. The lower end of transmission 960 includes a finger headmounting receptacle 954. Receptacle 954 is advantageously provided witha locking feature included to secure the fingers in the receptacles. Asshown, the receptacle includes a convoluted, bayonet-type, locking pingroove 955. Locking pin groove 955 receives a transversely mountedfinger mounting pin 956 (see FIG. 32) which is a rolled or othersuitable pin secured in the head of the finger assembly.

[0201]FIGS. 29, 30, and 31 detail the preferred construction of theactuator transmissions 960. The transmissions include a transmissionbase 961 which is provided with a mounting cutout 962 which is borneupon by the retainers 951 when installed in the rotor. The base alsoincludes a central passageway within which is received a transmissionshaft 963. Shaft 963 can both pivot and move axially within the centralpassageway. The shaft and base 961 are constructed to interact in amanner which controls the relative motion of the shaft. This is done toprovide the compound pivotal and axial movement of the shaft and afinger 979 which is held therein. As shown, the inactive mechanism isprovided in the form of a shaft channel or groove 964 which is engagedby a shaft camming control member 965. The camming action of the grooveis provide by a helical advance over a pivotal movement range ofapproximately 60 degrees of rotation. The associate axial travel is inthe range of approximately 5-20 millimeters, more preferably about 10-15millimeters.

[0202] The camming control member 965 is advantageously in the form of aball 966 held into the groove 964 using a ball support fastener 967.Fastener 967 has a ball socket which receives portions of the ball.Fastener 967 also serves as a convenient electrical contact terminalwhen electricity is supplied to the fingers 979.

[0203] The shaft 963 is provided with an interior shaft passageway 968which receives a spring retainer 969. Spring retainer 969 has anengagement head which mechanically engages with a finger mounting spring938. The spring 938 serves to bias a finger assembly into a lockedposition using the locking pin 956 held in biased relationship by groove955. Spring retainer 969 is secured in the passageway by a set screw939.

[0204]FIG. 31 also shows that the transmission 960 preferably includes atransmission head 656. Transmission head 656 is connected to the upperend of shaft 963 using a bearing 657 which allows the shaft to pivotrelative to the head pieces 658 and 659. Head pieces 658 and 659 capturethe bearing between them, and are joined by head fasteners 660. The headfasteners 660 thread into a pair of head guide rods 661. Head guide rods661 are slidably received by two guide passageways 662 formed in thetransmission base 961. The head assembly is biased upwardly by two headbias springs 664. Engagement between ball 966 and groove 964 limits theupward movement of the head assembly under action by springs 664.

[0205] The lower end of shaft 963 is sealed to the base 961 using ashaft seal 667 which helps to keep any abraded metal within thetransmission and prevent contamination toward the fingers 979. Shaft 963also has a transverse hole 665 which is used as an electrical connectionfeature that receives a wire (not shown) run from the slip ring down therotor shaft. The wire is secured in hole 665 by a set screw (not shown).

[0206] The transmissions 960 are activated by a transmission headdepression ring 683 (see FIG. 24). Depression ring 683 is connected toan operator output connection ring 684 (see FIG. 25). The operatoroutput connection ring is secured by fasteners to the output shafts ofpneumatic actuator engines 691. FIG. 25 also shows pneumatic manifolds692 used to supply the actuator engines. The preferred constructionshows three actuator engines 691 which have outputs which move upwardlyand downwardly to depress the transmission heads 658 and operate thefingers in the compound axial and pivotal motion already described. Theactuator engine outputs are extended to depress rings 683 and 684, andto depress the transmission heads 658 thus causing the fingers 979 tomove from the inboard retracted positions of FIG. 28 to the outboardextended positions of FIG. 27.

[0207] Electrode Fingers With Submerged Conductive Current TransferAreas

[0208] FIGS. 32-39 show a number of different electrode fingerconstructions. The different constructions shown have particularapplication to differing applications. FIG. 32 shows a finger assembly631 having intended application for contacting a semiconductor waferduring blanket plating of copper. Finger assembly 631 includes a fingershaft 632 which is formed in a J-shape and made from an electricallyconductive material, such as stainless steel or tungsten. The fingerassembly also preferably includes an integral finger head 633 which isreceived into the receptacle 954 of the actuator transmission 960. Thehead has a pin aperture which receives the locking pin 956 therein forengagement with the locking groove 955 formed in the receptacle of theactuator transmission.

[0209] Finger assembly 631 also preferably includes dielectric sheathing634 and 635. Dielectric sheathing 634 and 635 is advantageously madefrom a polyvinylidene fluoride coating or layer applied to the shaft ofthe finger. The dielectric sheathing is preferably provided upon onlylimited portions of the electrode shaft and adjacent the contact head636. The contact head has a contact face 637 which directly bears uponthe wafer to pass electrical current between the electrode and wafer.The contact face 637 is approximately equal to a fluid submersionboundary 639. The submersion boundary indicates the approximate level ofthe plating liquid during processing.

[0210] The limited coverage of the dielectric sheathing is for thepurpose of improving the uniformity of plating performed uponsemiconductor workpieces held in the wafer support. It is believed thatthe submersible surfaces of the electrode finger are best provided withdielectric sheathing segments which comprise between approximately 25percent and 75 percent of the submersible area of the electrode. Theseamounts do not consider the contact face as part of the areas. FIG. 32show two segments 634 and 635 which cover about 50 percent of theelectrode finger shaft exterior surfaces from the submersion line 639downward, as positioned in a plating liquid bath during processing. Thefirst dielectric segment 634 is adjacent to the contact face 637, afirst electrically conductive segment 642 exists between the dielectricsegment 634 and the contact face 637. A second electrically conductivesegment 643 exists between first and second dielectric segments 634 and635. A third electrically conductive segment 644 exists between thesecond dielectric segment 635 and submersion line 639. The electricallyconductive segments 642-644 provide current transfer areas which causeplating current that is supplied through the finger head 633 to bedirectly passed to the plating liquid contained in a plating bath. Thisis believed to provide a more uniform current density and more uniformvoltage profile across the surface of a wafer which is being blanketplated with copper or other plating metals.

[0211]FIG. 33 shows another plating system workpiece support electrode651 having many of the same features as electrode 631 describedimmediately above. The same reference numerals have been used todesignate similar parts. Differences between finger electrodes 651 and631 will now be described. Electrode 651 has three current transferareas 642-644. The size and shape of areas 642-644 are somewhatdifferent from the corresponding areas of electrode 631. Morespecifically, the second and third current transfer areas 643 and 644are elongated along the shaft. The second dielectric sheath segment 635is shortened. A third dielectric segment 653 has been included. Thethird dielectric sheath 654 forms the submerged dielectric segment 653and also extends above the submersion line 639 to head 633. The area ofthe submerged current transfer segments is between 25 and 75 percent ofthe submerged surface area, more particularly, about 50 percent.

[0212] Electrode 651 is also provided with a distal contact insert part655. Insert part 655 is received within an insert receptacle 616 formedin the distal end of the electrode shaft. The insert contact tip 655defines a contact face 617 which bears upon a wafer being held. Theinsert contact part is made from a conductive material which ispreferably non-corrosive material, such as platinum or stainless steel.

[0213]FIG. 34 shows a further electrode finger construction in the formof electrode finger 979. Similar parts to electrode fingers 631 and 651are similarly numbered in this figure. The electrode shaft is covered bya dielectric sheath 621 which largely covers the electrode shaft andleaves only a first current conductive area 642 which is immediatelyadjacent to the contact face 637. This construction is contrasted to theelectrodes 631 and 651 because electrode finger 979 does not havecurrent transfer areas which comprise 25 percent of the submergedportion of the electrode. It also does not have current transfer areaswhich are exposed in a manner which is separated by a dielectric segmentinterpositioned between the contact face 637 and the removed or remotecurrent conductive segment.

[0214]FIG. 35 shows a further electrode finger 601 which has submergedcurrent transfer areas 642-644. It also has dielectric segments 634 and635. Dielectric segment 635 of this figure has a differing shape andcoverage area as compared to the other electrodes discussed above. Inthis construction the dielectric sheath extends along the outercurvature of the electrode J-bend. Curved upper edges extend so as toprovide an overlying web portion 603 which covers the inner curvature ofthe J-bend. Performance in terms of plating uniformity has been found tobe superior in some processes which employed the electrode of thisfigure.

[0215] The electrodes 631, 651 and 601 are preferably used in novelprocesses according to this invention. These processes includecontacting a surface of the semiconductor article or workpiece with anelectrode at a contact face thereof. The methods also include submersinga portion or portions of the electrode into a plating bath containing aplating liquid which is typically a solution and mixture have variouscomponents known in the art. The methods also preferably include wettinga processed surface of the semiconductor article with the plating bath.Further included is the step of moving or conducting electrical currentthrough the electrode and plating bath to perform an electroplatingaction to occur upon at least the processed surface of the wafer orother article. The methods further advantageously include diverting aportion of the electrical current directly between the electrode and theplating bath along at least one electrically conductive segment of theelectrode. The electrically conductive segment is preferably spaced fromthe contact face a substantial distance, such as greater than 5millimeters, and preferably is spaced therefrom by an interveningdielectric sheath.

[0216] Electrode Fingers With Dielectric Sheaths Covering SubmergedAreas

[0217]FIG. 36 shows another electrode finger 681 which is similar toelectrode finger 651. Finger 681 is similar to finger 651 except itincludes a full dielectric sheath 682 which extends from abovesubmersion line 639 to contact insert side walls 619. This constructionpreferably uses a coating layer 682, such as from polyvinylidenefluoride, which can be applied by dipping or otherwise forming the layerover the shaft of the electrode. This construction includes thedielectric layer over the distal end of the electrode shaft and intosealing relationship with the side walls of the insert contact part ortip 655. The dielectric coating or other layer 682 excludes corrosiveprocessing fluids. Since the contact tip is preferably made from anon-corrosive material, such as platinum, the only material of theelectrode which is exposed to direct corrosive action is thenon-corrosive tip which is able to maintain good service despite thedifficult operating environment.

[0218] Additionally, the construction of electrode 681 is particularlyadvantageous because the joint formed between the inserted contact tip655 and receptacle 616 is covered and protected from direct exposure tothe corrosive plating liquid and fumes present in the processingchamber.

[0219] The invention further includes methods for plating metals ontothe surface of a semiconductor workpiece using electrode finger 681. Themethods include contacting a surface of the workpiece with an electrodeassembly using a contact face, such as face 617, on a contact part, suchas contact insert part 655. The contact insert is mounted on the distalend of the electrode shaft. It is further preferably provided with adielectric layer formed about the distal end in sealing relationshipagainst the contact part. The methods further preferably includesubmersing or otherwise wetting a processed surface of the workpiece,such as in a plating bath liquid used to plate the workpiece with aplating material. The methods also preferably include excluding theplating bath liquified from the contact part joint, such as the jointformed between the contact part 655 and receptacle 616. The methodsfurther include electroplating the workpiece with plating material bypassing electrical current through the contact part and between thesemiconductor workpiece and electrode assembly. The contact fact platinglayer is more preferably formed from the plating material as isdescribed below in additional detail. The method is most preferably usedto plate copper onto the surface of semiconductor materials, such assilicon or oxides thereof.

[0220] Pre-Conditioning of Electrode Contact Faces

[0221]FIGS. 37 and 38 illustrates a further electrode construction inaccordance with further inventive aspects of the workpiece supportsystems and methods described herein. FIG. 37 shows distal end portionsof an electrode 614. Electrode 614 is otherwise similar to electrode 681described above. At the distal end of electrode finger 614 is a distalexposed surface 615 is made from a suitable material, such as stainlesssteel or tungsten. A dielectric sheath 616 is advantageously providedalong the exterior portions of the electrode adjacent to the distalexposed surface 615.

[0222]FIG. 38 shows the electrode 614 with a deposited contact faceplating layer 618 formed thereon. The layer 618 is preferably a layermade from the same or a very similar material as is being plated ontothe semiconductor workpieces with which electrode 614 is to be used. Forexample, if copper is being plated onto the semiconductor device, thenthe layer 618 is a layer plated from the same plating bath or from aplating bath which will provide a layer 618 which is the same or verysimilar to the constituency of the copper deposited onto thesemiconductor device being plated. In a preferred manner of carrying outthis invention, the exposed distal surfaces 615 are placed into aplating bath and electrical current is conducted through the bath anddistal end of the electrode 614. This causes a plating action to occurwhich deposits the layer 618. The resulting layer is preferably at least1 micron in thickness, more preferably in the approximate range of 1-100microns thick.

[0223] This method and resulting construction results in apre-conditioned electrode contact surface which is of the same or verysimilar material as plated onto the semiconductor device during thelater plating operation. The use of the same or similar materialsprevents galvanic or other types of chemical reactions from developingdue to dissimilarity of the metals involved.

[0224] The invention further includes additional methods for platingmetals onto the surface of a semiconductor workpiece. The preferredmethods include contacting a surface of the semiconductor workpiece withan electrode at a contact face forming a part of the electrode. Thecontact face is covered or substantially covered by a contact faceplating layer. The contact face plating layer is formed from a contactface plating material which is the same or chemically similar to theeplating material which is to be plated onto the semiconductor workpieceduring processing. The methods also preferably include submersing orotherwise wetting a processed surface of the workpiece into a platingbath or using a plating liquid or fluid. Other means for depositing theplating material as a contact face layer may alternatively be used. Themethods further include electroplating workpiece plating material ontothe semiconductor workpiece by passing electrical current between theworkpiece and the electrode having such contact face plating layer. Themethods are of particular advantage in the plating of copper ontosemiconductors using a copper contact face plating layer.

[0225] Methods Using Workpiece-Engaging Electrode Assembly With SealingBoot

[0226]FIG. 39 shows a further electrode finger 583 which has featuressimilar to 651 and such similar features are identified with the samereference numbers. Electrode finger 583 differs from finger 651 in thatthe electrode shaft 584 is covered between the head 633 to the distalend of the electrode shaft with a cover or boot 585. Boot 585 ispreferably made in a manner which provides a continuous cover from nearthe electrode head 633 to a distal contact lip 586. The boot includesadditional features adjacent the contact insert part 655. Morespecifically, the boot includes a skirt portion 587 which extends abovethe electrode shaft distal end surface 588. The contact face 617 of theinsert part 655 is preferably about even with the distal contact lip 586which is formed upon the end of the skirt portion 587. The skirt portionserves as a deformable seal which comes into contact with a surface of awafer or other semiconductor workpiece being contacted.

[0227]FIGS. 40 and 41 illustrate novel methods which advantageouslyutilize the improved features of electrode finger 583. The methodsinvolve plating metals onto the surface of semiconductor workpieces,specifically onto a semiconductor wafer W which has a substrate or othersubjacent layer 561 which has been previously provided with a thinmetallic seed layer 562 which is shown by a heavy black line in thatfigure. A via or other opening 563 exists in a photoresist layer 564which overlies the substrate and seed layers.

[0228]FIG. 40 shows the electrode 583 poised in a disengaged position inpreparation for contact with the surface. FIG. 41 shows the electrode583 retracted against the surface of the workpiece. In the engagedposition the contact face 617 is extended through the opening 563 andinto direct electrical contact with exposed areas of the seed layer 562which are not covered by the layer of photoresist or other coveringlayer. A seal is formed by depressing the skirt 587 and attached lip 586against the outer surface of the photoresist layer 564.

[0229] The novel methods include selecting an electrode assembly havingdesired features, such the features of electrode finger 583. Morespecifically, the selecting step preferably includes selecting anelectrode assembly having an electrode contact which is surrounded by anelectrode boot or other sealing member. The methods also includeengaging coated surface portions, such as photoresist layer 564, withthe sealing member or boot. The sealing can occur about a continuousperipheral sealing line, such as defined by the engagement of lip 586against the photoresist surface. It is important to engage the lipagainst the photoresist surface and not against the seed layer 562because sealing against the seed layer can cause erosive or corrosiveeffects to occur at or near the line or area of engagement of the bootwith the seed layer. Such erosive or corrosive actions can cause theseed layer to become discontinuous or even totally isolated. Adiscontinuous or isolated contact region will lead to electroplatingfailure because the needed current will not be communicated in an evenmanner to the areas adjacent to the electrode which need current toaccomplish plating. The engagement of the seal against the coatingcauses a sealed space to be enclosed within the seal by the electrodeboot and the processed surface of the workpiece.

[0230] The novel methods further include enclosing a via or otheropening within the seal. The via is present on the processed surface andhas associated exposed seed layer portions therein for allowingelectrical contact to be made. The via is needed to allow direct contactbetween the contact face of the electrode finger assembly and the seedlayer which is used to communicate electrical current across the waferfor electroplating a metal thereonto. Thus, the methods further includecontacting the seed layer through the via with the electrode contact toform an electrically conductive connection between the electrodeassembly and the seed layer. This contacting step is advantageouslyperformed using a contact face which bears upon the seed layer and isenclosed with the sealed space. Other desirable attributes explainedhereinabove in connection with other electrodes can also be utilized toadvantage in performing this process.

[0231] The methods still further include wetting the processed surfaceof the workpiece with a plating or other processing liquid. This istypically done by lowering the wafer holder into position to bring theouter, processed surface of the wafer into direct contact with a platingliquid held in a plating bath, such as described elsewhere herein inadditional detail.

[0232] The methods also preferably include passing electrical currentthrough the electrode and plating bath to cause electroplating to occurupon exposed seed layer areas of the processed surface. Such exposedseed layer areas may be trenches, vias or other features where thephotoresist layer 564 is not present to cover the seed layer 562. Theelectrical current causes electroplating to occur on such exposed seedlayer areas.

[0233] Still further, the methods preferably include excluding platingor other processing liquid from the sealed space to substantially reduceor eliminate plating or other action in the area immediate adjacent tothe contact with the electrode.

[0234] The methods described above are of particular relevance toplating copper onto semiconductors.

[0235] Plating Bowl Assembly

[0236]FIG. 42 shows an electroplating bowl assembly 303. The processbowl assembly consists of a process bowl or plating vessel 316 having anouter bowl side wall 617, bowl bottom 319, and bowl rim assembly 314.The process bowl is preferably circular in horizontal cross-section andgenerally cylindrical in shape although other shapes of process bowl maybe possible.

[0237] The invention further advantageously includes a cup assembly 320which is disposed within process bowl vessel 316. Cup assembly 320includes a fluid cup portion 321 having a cup side 322 and a cup bottom323. As with the outer process bowl, the fluid cup 321 is preferablycircular in horizontal cross-section and cylindrical in shape. The cupassembly also has a depending skirt 371 which extends below the cupbottom 323 and has flutes 372 open therethrough for fluid communicationand release of any gas that might collect as the chamber below fillswith liquid. The cup assembly can be made using upper and lower portionswhich couple together at a cup main joint 387. The cup is preferablymade from polypropylene or other suitable material, which isadvantageously dielectric.

[0238] The lower opening in the cup bottom wall is connected to a risertube 361 which is adjustable in height relative thereto by a threadedconnection. The riser tube seals between the bottom wall 319 of theprocess bowl and the cup bottom 323. The riser tube is preferably madefrom polypropylene or other suitable dielectric material. A fitting 362connects the riser tube 361 and the fluid inlet line 325 to allowadjustment of the anode vertical position. The fitting 362 canaccommodate height adjustment of both the riser tube and inlet line 325.The inlet line is made from a conductive material, such as titanium andis used to conduct electrical current to the anode 324, as well assupply fluid to the cup.

[0239] Process fluid is provided to the cup through fluid inlet line325. The fluid inlet line rises through riser tube 361 and bowl bottomopening 327 and through cup fluid inlet openings 324. Placing fluidfills the cup portion 321 through opening 324 as supplied by a platingfluid pump (not shown) or other suitable supply which provides the fluidunder at least some pressure for delivery.

[0240] The upper edge of the cup side wall 322 forms a weir whichdetermines the level of plating liquid within the cup. Excess fluidpours over this top edge surface into the overflow chamber 345. Thefluid held in the overflow chamber 345 is sensed by two level detectors351 and 352. One level detector is used to sense a desired high leveland the other is used to sense an overfull condition. The level ofliquid is preferably maintained within a desired range for stability ofoperation. This can be done using several different outflowconfigurations. A preferred configuration is to sense the high levelusing detector 351 and then drain fluid through a drain line ascontrolled by a control valve. It is also possible to use a standpipearrangement (not illustrate), and such is used as a final overflowprotection device in the preferred plating station 303. More complexlevel controls are also possible.

[0241] The outflow liquid from chamber 345 is preferably returned to asuitable reservoir. The liquid can then be treated with additionalplating chemicals or other constituents of the plating or other processliquid and used again.

[0242] The plating bowl assembly 303 further includes an anode 334. Inthe preferred uses according to this invention, the anode is aconsumable anode used in connection with the plating of copper or othermetals onto semiconductor materials. The specific anode will varydepending upon the metal being plated and other specifics of the platingliquid being used. A number of different consumable anodes which arecommercially available may be used as anode 334.

[0243]FIG. 42 also shows a diffusion plate 375 provide above the anode334 for rendering the fluid plating bath above the diffusion plate withless turbulence. Fluid passages are provided over all or a portion ofthe diffusion plate to allow fluid communication therethrough. Theheight of the diffusion plate is adjustable using three diffuser heightadjustment mechanisms 386 and secured by three mounting fasteners 389.

[0244] Plating Anode Shield

[0245] The invention also includes an anode shield 393 which can besecured to the consumable anode 334 using anode shield fasteners 394.The anode shield and anode shield fasteners are preferably made from adielectric material, such as polyvinylidene fluoride or polypropylene.The anode shield is advantageously about 2-5 millimeters thick, morepreferably about 3 millimeters thick.

[0246] The anode shield serves to electrically isolate and physicallyprotect the back side of the anode. It also reduces the consumption oforganic plating liquid additives consumed. Although the exact mechanismmay not be known at this time, the anode shield is believed to preventdisruption of certain materials which develop over time on the back sideof the anode. If the anode is left unshielded the organic chemicalplating additives are consumed at a significantly greater rate. With theshield in place these additive are consumed less. The shield ispreferably positioned on the anode so as to shield it from directimpingement by the incoming plating liquid.

[0247] The invention thus also include methods for plating which includeother method steps described herein in combination with shielding aconsumable anode from direct flow of plating liquids using a dielectricanode shield.

[0248] In compliance with the statute, the invention has been describedin language more or less specific as to structural and methodicalfeatures. It is to be understood, however, that the invention is notlimited to the specific features shown and described, since the meansherein disclosed comprise preferred forms of putting the invention intoeffect. The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

I claim
 1. A semiconductor workpiece support for use in processing asemiconductor workpiece, comprising: a processing head mounted forcontrolled motion to allow the processing head to be mated with aprocessing bowl to confine a processing chamber therebetween; a rotormounted for controlled rotation upon the processing head, said rotorhaving a front face which is exposed to the processing chamber and aback face opposite to said front face; a workpiece holder for holdingthe semiconductor workpiece in juxtaposition to the front face of therotor; a beam emitter for emitting an emitted optical beam from alocation behind the back face of the rotor; a beam detector fordetecting any reflected optical beam which results from said emittedoptical beam if said emitted optical beam is reflected from a workpieceheld by the workpiece holder.
 2. The semiconductor workpiece support ofclaim 1 wherein said detector can operate in a mode which discriminateson the angle of any reflected optical beam.
 3. The semiconductorworkpiece support of claim 1 wherein said beam detector is defined toinclude at least a pair of detectors.
 4. The semiconductor workpiecesupport of claim 1 and further comprising at least one window providedin the rotor to improve transmission of the emitted or reflected beams.5. A semiconductor workpiece support for use in processing asemiconductor workpiece, comprising: a processing head; a rotor mountedfor controlled rotation upon the processing head, said rotor having afront face which is exposed to a processing chamber and a back faceopposite to said front face; a workpiece holder for holding thesemiconductor workpiece in juxtaposition to the front face of the rotor;a beam emitter for emitting an emitted optical beam from a locationbehind the back face of the rotor; a beam detector for detecting anyreflected optical beam which results from said emitted optical beam ifsaid emitted optical beam is reflected from a workpiece held by theworkpiece holder.
 6. The semiconductor workpiece support of claim 5wherein said detector can operate in a mode which discriminates on theangle of any reflected optical beam.
 7. The semiconductor workpiecesupport of claim 5 wherein said beam detector is defined to include atleast a pair of detectors.
 8. The semiconductor workpiece support ofclaim 5 and further comprising at least one window provided in the rotorto improve transmission of the emitted or reflected beams.
 9. Asemiconductor workpiece support for use in processing a semiconductorworkpiece, comprising: a processing head; a workpiece holder for holdingthe semiconductor workpiece in juxtaposition to a workpiece holderpanel; a beam emitter for emitting an emitted optical beam from alocation behind the workpiece holder panel, said emitted optical beampassing through said workpiece holder panel; a beam detector fordetecting any reflected optical beam which results from said emittedoptical beam if said emitted optical beam is reflected from a workpieceheld by the workpiece holder.
 10. The semiconductor workpiece support ofclaim 9 wherein said detector can operate in a mode which discriminateson the angle of any reflected optical beam.
 11. The semiconductorworkpiece support of claim 9 wherein said beam detector is defined toinclude at least a pair of detectors.
 12. The semiconductor workpiecesupport of claim 9 and further comprising at least one window providedin the workpiece holder panel.
 13. A method for detecting asemiconductor workpiece held by a workpiece holder forming part of arotor which is rotatably mounted on a processing head mounted forcontrolled motion to allow the processing head to be mated with aprocessing bowl to confine a processing chamber therebetween,comprising: positioning the rotor at a suitable location relative to abeam emitter and beam detector; emitting an emitted optical beam fromthe beam emitter through a rotor panel and against any workpiece beingheld by the workpiece holder; detecting to determine whether there isreflected optical beam which indicates that a workpiece is held in theworkpiece holder.
 14. A method according to claim 13 and further definedby emitting the emitted optical beam through a window forming part ofthe rotor.
 15. A method according to claim 13 and further defined bydiscriminating in said detecting step to detect a reflected beam whichis incident upon at least one detector at an angle associated withreflection from any workpiece present.
 16. A method according to claim13 and further defined by discriminating in said detecting step todetect a reflected beam which is incident upon at least one detector atan angle associated with reflection from any workpiece present, andminimizing detection of any beam reflected from surfaces of said rotor.